diff --git a/src/AbstractMapper.php b/src/AbstractMapper.php
index 992e2eb..0ebda23 100644
--- a/src/AbstractMapper.php
+++ b/src/AbstractMapper.php
@@ -30,10 +30,12 @@ abstract class AbstractMapper
     /** @var array<string, Collection> */
     private array $collections = [];
 
+    public EntityFactory $entityFactory { get => $this->hydrator->entityFactory; }
+
     public Styles\Stylable $style { get => $this->entityFactory->style; }
 
     public function __construct(
-        public readonly EntityFactory $entityFactory = new EntityFactory(),
+        public readonly Hydrator $hydrator,
     ) {
         $this->tracked = new SplObjectStorage();
         $this->pending = new SplObjectStorage();
@@ -130,8 +132,6 @@ public function registerCollection(string $alias, Collection $collection): void
         $this->collections[$alias] = $collection;
     }
 
-    abstract protected function defaultHydrator(Collection $collection): Hydrator;
-
     /**
      * @param array<string, mixed> $columns
      *
@@ -153,11 +153,6 @@ protected function filterColumns(array $columns, Collection $collection): array
         return array_intersect_key($columns, array_flip([...$collection->filters, $id]));
     }
 
-    protected function resolveHydrator(Collection $collection): Hydrator
-    {
-        return $collection->hydrator ?? $this->defaultHydrator($collection);
-    }
-
     protected function registerInIdentityMap(object $entity, Collection $coll): void
     {
         if ($coll->name === null) {
diff --git a/src/Collections/Collection.php b/src/Collections/Collection.php
index a344cb5..92f0bac 100644
--- a/src/Collections/Collection.php
+++ b/src/Collections/Collection.php
@@ -7,7 +7,6 @@
 use ArrayAccess;
 use Respect\Data\AbstractMapper;
 use Respect\Data\CollectionNotBound;
-use Respect\Data\Hydrator;
 
 /** @implements ArrayAccess<string, Collection> */
 class Collection implements ArrayAccess
@@ -16,8 +15,6 @@ class Collection implements ArrayAccess
 
     public private(set) AbstractMapper|null $mapper = null;
 
-    public private(set) Hydrator|null $hydrator = null;
-
     public private(set) Collection|null $parent = null;
 
     public private(set) Collection|null $connectsTo = null;
@@ -101,13 +98,6 @@ public function bindMapper(AbstractMapper $mapper): static
         return $this;
     }
 
-    public function hydrateFrom(Hydrator $hydrator): static
-    {
-        $this->hydrator = $hydrator;
-
-        return $this;
-    }
-
     public function stack(Collection $collection): static
     {
         $tail = $this->last ?? $this;
diff --git a/src/Hydrator.php b/src/Hydrator.php
index 4fc6770..7bed807 100644
--- a/src/Hydrator.php
+++ b/src/Hydrator.php
@@ -10,10 +10,17 @@
 /** Transforms raw backend data into entity instances mapped to their collections */
 interface Hydrator
 {
-    /** @return SplObjectStorage<object, Collection>|false */
+    public EntityFactory $entityFactory { get; }
+
+    /** Returns just the root entity */
     public function hydrate(
         mixed $raw,
         Collection $collection,
-        EntityFactory $entityFactory,
+    ): object|false;
+
+    /** @return SplObjectStorage<object, Collection>|false */
+    public function hydrateAll(
+        mixed $raw,
+        Collection $collection,
     ): SplObjectStorage|false;
 }
diff --git a/src/Hydrators/Base.php b/src/Hydrators/Base.php
index 2acaf79..dbf09aa 100644
--- a/src/Hydrators/Base.php
+++ b/src/Hydrators/Base.php
@@ -4,6 +4,7 @@
 
 namespace Respect\Data\Hydrators;
 
+use DomainException;
 use Respect\Data\Collections\Collection;
 use Respect\Data\Collections\Typed;
 use Respect\Data\EntityFactory;
@@ -13,10 +14,35 @@
 /** Base hydrator providing collection-tree entity wiring */
 abstract class Base implements Hydrator
 {
+    public function __construct(
+        public readonly EntityFactory $entityFactory = new EntityFactory(),
+    ) {
+    }
+
+    public function hydrate(
+        mixed $raw,
+        Collection $collection,
+    ): object|false {
+        $entities = $this->hydrateAll($raw, $collection);
+        if ($entities === false) {
+            return false;
+        }
+
+        foreach ($entities as $entity) {
+            if ($entities[$entity] === $collection) {
+                return $entity;
+            }
+        }
+
+        throw new DomainException(
+            'Hydration produced no entity for collection "' . $collection->name . '"',
+        );
+    }
+
     /** @param SplObjectStorage<object, Collection> $entities */
-    protected function wireRelationships(SplObjectStorage $entities, EntityFactory $entityFactory): void
+    protected function wireRelationships(SplObjectStorage $entities): void
     {
-        $style = $entityFactory->style;
+        $style = $this->entityFactory->style;
         $others = clone $entities;
 
         foreach ($entities as $entity) {
@@ -40,12 +66,12 @@ protected function wireRelationships(SplObjectStorage $entities, EntityFactory $
                     continue;
                 }
 
-                $id = $entityFactory->get($other, $style->identifier($otherColl->name));
+                $id = $this->entityFactory->get($other, $style->identifier($otherColl->name));
                 if ($id === null) {
                     continue;
                 }
 
-                $entityFactory->set($entity, $relationName, $other);
+                $this->entityFactory->set($entity, $relationName, $other);
             }
         }
     }
@@ -57,13 +83,12 @@ protected function wireRelationships(SplObjectStorage $entities, EntityFactory $
      */
     protected function resolveEntityClass(
         Collection $collection,
-        EntityFactory $entityFactory,
         object|array $row,
     ): string {
         if ($collection instanceof Typed) {
-            return $collection->resolveEntityClass($entityFactory, $row);
+            return $collection->resolveEntityClass($this->entityFactory, $row);
         }
 
-        return $entityFactory->resolveClass((string) $collection->name);
+        return $this->entityFactory->resolveClass((string) $collection->name);
     }
 }
diff --git a/src/Hydrators/Nested.php b/src/Hydrators/Nested.php
index 8a45158..ac89031 100644
--- a/src/Hydrators/Nested.php
+++ b/src/Hydrators/Nested.php
@@ -5,7 +5,6 @@
 namespace Respect\Data\Hydrators;
 
 use Respect\Data\Collections\Collection;
-use Respect\Data\EntityFactory;
 use SplObjectStorage;
 
 use function is_array;
@@ -14,10 +13,9 @@
 final class Nested extends Base
 {
     /** @return SplObjectStorage<object, Collection>|false */
-    public function hydrate(
+    public function hydrateAll(
         mixed $raw,
         Collection $collection,
-        EntityFactory $entityFactory,
     ): SplObjectStorage|false {
         if (!is_array($raw)) {
             return false;
@@ -26,10 +24,10 @@ public function hydrate(
         /** @var SplObjectStorage<object, Collection> $entities */
         $entities = new SplObjectStorage();
 
-        $this->hydrateNode($raw, $collection, $entityFactory, $entities);
+        $this->hydrateNode($raw, $collection, $entities);
 
         if ($entities->count() > 1) {
-            $this->wireRelationships($entities, $entityFactory);
+            $this->wireRelationships($entities);
         }
 
         return $entities;
@@ -42,11 +40,10 @@ public function hydrate(
     private function hydrateNode(
         array $data,
         Collection $collection,
-        EntityFactory $entityFactory,
         SplObjectStorage $entities,
     ): void {
-        $entity = $entityFactory->create(
-            $this->resolveEntityClass($collection, $entityFactory, $data),
+        $entity = $this->entityFactory->create(
+            $this->resolveEntityClass($collection, $data),
         );
 
         foreach ($data as $key => $value) {
@@ -54,17 +51,17 @@ private function hydrateNode(
                 continue;
             }
 
-            $entityFactory->set($entity, $key, $value);
+            $this->entityFactory->set($entity, $key, $value);
         }
 
         $entities[$entity] = $collection;
 
         if ($collection->connectsTo !== null) {
-            $this->hydrateChild($data, $collection->connectsTo, $entityFactory, $entities);
+            $this->hydrateChild($data, $collection->connectsTo, $entities);
         }
 
         foreach ($collection->children as $child) {
-            $this->hydrateChild($data, $child, $entityFactory, $entities);
+            $this->hydrateChild($data, $child, $entities);
         }
     }
 
@@ -75,7 +72,6 @@ private function hydrateNode(
     private function hydrateChild(
         array $parentData,
         Collection $child,
-        EntityFactory $entityFactory,
         SplObjectStorage $entities,
     ): void {
         $key = $child->name;
@@ -85,6 +81,6 @@ private function hydrateChild(
 
         /** @var array<string, mixed> $childData */
         $childData = $parentData[$key];
-        $this->hydrateNode($childData, $child, $entityFactory, $entities);
+        $this->hydrateNode($childData, $child, $entities);
     }
 }
diff --git a/src/Hydrators/PrestyledAssoc.php b/src/Hydrators/PrestyledAssoc.php
index 9d9c8e9..83137bd 100644
--- a/src/Hydrators/PrestyledAssoc.php
+++ b/src/Hydrators/PrestyledAssoc.php
@@ -9,7 +9,6 @@
 use Respect\Data\Collections\Collection;
 use Respect\Data\Collections\Composite;
 use Respect\Data\Collections\Filtered;
-use Respect\Data\EntityFactory;
 use SplObjectStorage;
 
 use function array_keys;
@@ -31,10 +30,9 @@ final class PrestyledAssoc extends Base
     private Collection|null $cachedCollection = null;
 
     /** @return SplObjectStorage<object, Collection>|false */
-    public function hydrate(
+    public function hydrateAll(
         mixed $raw,
         Collection $collection,
-        EntityFactory $entityFactory,
     ): SplObjectStorage|false {
         if (!$raw || !is_array($raw)) {
             return false;
@@ -59,19 +57,19 @@ public function hydrate(
 
             if (!isset($instances[$basePrefix])) {
                 $coll = $collMap[$basePrefix];
-                $class = $this->resolveEntityClass($coll, $entityFactory, $props);
-                $instances[$basePrefix] = $entityFactory->create($class);
+                $class = $this->resolveEntityClass($coll, $props);
+                $instances[$basePrefix] = $this->entityFactory->create($class);
                 $entities[$instances[$basePrefix]] = $coll;
             }
 
             $entity = $instances[$basePrefix];
             foreach ($props as $prop => $value) {
-                $entityFactory->set($entity, $prop, $value, styled: true);
+                $this->entityFactory->set($entity, $prop, $value, styled: true);
             }
         }
 
         if ($entities->count() > 1) {
-            $this->wireRelationships($entities, $entityFactory);
+            $this->wireRelationships($entities);
         }
 
         return $entities;
diff --git a/tests/AbstractMapperTest.php b/tests/AbstractMapperTest.php
index 306c002..f0fe9cc 100644
--- a/tests/AbstractMapperTest.php
+++ b/tests/AbstractMapperTest.php
@@ -22,8 +22,8 @@ class AbstractMapperTest extends TestCase
 
     protected function setUp(): void
     {
-        $factory = new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\');
-        $this->mapper = new class ($factory) extends AbstractMapper {
+        $hydrator = new Nested(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $this->mapper = new class ($hydrator) extends AbstractMapper {
             public function flush(): void
             {
             }
@@ -38,11 +38,6 @@ public function fetchAll(Collection $collection, mixed $extra = null): array
             {
                 return [];
             }
-
-            protected function defaultHydrator(Collection $collection): Hydrator
-            {
-                return new Nested();
-            }
         };
     }
 
@@ -104,7 +99,7 @@ public function getStyleShouldReturnSameInstanceOnSubsequentCalls(): void
     public function styleShouldComeFromEntityFactory(): void
     {
         $style = new CakePHP();
-        $mapper = new class (new EntityFactory(style: $style)) extends AbstractMapper {
+        $mapper = new class (new Nested(new EntityFactory(style: $style))) extends AbstractMapper {
             public function flush(): void
             {
             }
@@ -119,11 +114,6 @@ public function fetchAll(Collection $collection, mixed $extra = null): array
             {
                 return [];
             }
-
-            protected function defaultHydrator(Collection $collection): Hydrator
-            {
-                return new Nested();
-            }
         };
         $this->assertSame($style, $mapper->style);
     }
@@ -223,7 +213,9 @@ public function magicGetShouldReturnNewCollectionWhenNotRegistered(): void
     #[Test]
     public function hydrationWiresRelatedEntity(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('comment', [
             ['id' => 1, 'text' => 'Hello', 'post_id' => 5],
         ]);
@@ -244,7 +236,9 @@ public function hydrationWiresRelatedEntity(): void
     #[Test]
     public function persistAfterHydrationPreservesRelation(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('comment', [
             ['id' => 1, 'text' => 'Hello', 'post_id' => 5],
         ]);
@@ -269,7 +263,9 @@ public function persistAfterHydrationPreservesRelation(): void
     #[Test]
     public function hydrationWithNoMatchLeavesRelationNull(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('comment', [
             ['id' => 1, 'text' => 'Hello', 'post_id' => 999],
         ]);
@@ -286,7 +282,9 @@ public function hydrationWithNoMatchLeavesRelationNull(): void
     #[Test]
     public function hydrationWiresRelationWithStringPk(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('comment', [
             ['id' => 1, 'text' => 'Hello', 'post_id' => 5],
         ]);
@@ -304,7 +302,9 @@ public function hydrationWiresRelationWithStringPk(): void
     #[Test]
     public function callingRegisteredCollectionClonesAndAppliesCondition(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Hello'],
             ['id' => 2, 'title' => 'World'],
@@ -325,7 +325,9 @@ public function callingRegisteredCollectionClonesAndAppliesCondition(): void
     #[Test]
     public function callingRegisteredCollectionWithoutConditionReturnsClone(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $coll = Filtered::posts('title');
         $mapper->postTitles = $coll;
 
@@ -340,7 +342,9 @@ public function callingRegisteredCollectionWithoutConditionReturnsClone(): void
     #[Test]
     public function callingRegisteredChainedCollectionDoesNotMutateTemplate(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', []);
         $mapper->seed('comment', []);
 
@@ -360,7 +364,9 @@ public function callingRegisteredChainedCollectionDoesNotMutateTemplate(): void
     #[Test]
     public function filteredPersistDelegatesToParentCollection(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', []);
         $mapper->seed('author', []);
         $mapper->authorsWithPosts = Filtered::post()->author();
@@ -377,7 +383,9 @@ public function filteredPersistDelegatesToParentCollection(): void
     #[Test]
     public function filteredWithoutConnectsToFallsBackToNormalPersist(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', []);
 
         $post = new Stubs\Post();
@@ -392,7 +400,9 @@ public function filteredWithoutConnectsToFallsBackToNormalPersist(): void
     #[Test]
     public function filteredUpdatePersistsOnlyFilteredColumns(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Original', 'text' => 'Body'],
         ]);
@@ -414,7 +424,9 @@ public function filteredUpdatePersistsOnlyFilteredColumns(): void
     #[Test]
     public function filteredInsertPersistsOnlyFilteredColumns(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', []);
 
         $postTitles = Filtered::post('title');
@@ -434,7 +446,9 @@ public function filteredInsertPersistsOnlyFilteredColumns(): void
     #[Test]
     public function filterColumnsPassesThroughForPlainCollection(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Original', 'text' => 'Body'],
         ]);
@@ -455,7 +469,9 @@ public function filterColumnsPassesThroughForPlainCollection(): void
     #[Test]
     public function filterColumnsPassesThroughForEmptyFilters(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Original', 'text' => 'Body'],
         ]);
@@ -478,7 +494,9 @@ public function filterColumnsPassesThroughForEmptyFilters(): void
     #[Test]
     public function filterColumnsPassesThroughForIdentifierOnly(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Original', 'text' => 'Body'],
         ]);
@@ -501,7 +519,9 @@ public function filterColumnsPassesThroughForIdentifierOnly(): void
     #[Test]
     public function fetchPopulatesIdentityMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'First'],
             ['id' => 2, 'title' => 'Second'],
@@ -519,7 +539,9 @@ public function fetchPopulatesIdentityMap(): void
     #[Test]
     public function fetchReturnsCachedEntityFromIdentityMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'First'],
         ]);
@@ -533,7 +555,9 @@ public function fetchReturnsCachedEntityFromIdentityMap(): void
     #[Test]
     public function fetchAllPopulatesIdentityMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'First'],
             ['id' => 2, 'title' => 'Second'],
@@ -546,7 +570,9 @@ public function fetchAllPopulatesIdentityMap(): void
     #[Test]
     public function flushInsertRegistersInIdentityMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', []);
 
         $entity = new Stubs\Post();
@@ -560,7 +586,9 @@ public function flushInsertRegistersInIdentityMap(): void
     #[Test]
     public function flushDeleteEvictsFromIdentityMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'To Delete'],
         ]);
@@ -577,7 +605,9 @@ public function flushDeleteEvictsFromIdentityMap(): void
     #[Test]
     public function clearIdentityMapEmptiesMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'First'],
         ]);
@@ -592,7 +622,9 @@ public function clearIdentityMapEmptiesMap(): void
     #[Test]
     public function resetDoesNotClearIdentityMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'First'],
         ]);
@@ -607,7 +639,9 @@ public function resetDoesNotClearIdentityMap(): void
     #[Test]
     public function pendingOperationTypes(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Existing'],
         ]);
@@ -641,7 +675,9 @@ public function pendingOperationTypes(): void
     #[Test]
     public function trackedCountReflectsTrackedEntities(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'First'],
         ]);
@@ -655,7 +691,9 @@ public function trackedCountReflectsTrackedEntities(): void
     #[Test]
     public function registerSkipsEntityWithNullCollectionName(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $entity = new Stubs\Foo();
         $entity->id = 1;
 
@@ -670,7 +708,9 @@ public function registerSkipsEntityWithNullCollectionName(): void
     #[Test]
     public function registerSkipsEntityWithNoPkValue(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', []);
 
         // Entity with no 'id' set
@@ -686,7 +726,9 @@ public function registerSkipsEntityWithNoPkValue(): void
     #[Test]
     public function deleteEvictsUsingTrackedCollection(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Test'],
         ]);
@@ -704,7 +746,9 @@ public function deleteEvictsUsingTrackedCollection(): void
     #[Test]
     public function findInIdentityMapSkipsNonScalarCondition(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'First'],
         ]);
@@ -721,7 +765,9 @@ public function findInIdentityMapSkipsNonScalarCondition(): void
     #[Test]
     public function findInIdentityMapSkipsCollectionWithChildren(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('comment', [
             ['id' => 1, 'text' => 'Hello', 'post_id' => 5],
         ]);
@@ -737,7 +783,9 @@ public function findInIdentityMapSkipsCollectionWithChildren(): void
     #[Test]
     public function persistUntrackedEntityWithMatchingPkUpdates(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Original'],
         ]);
@@ -767,7 +815,9 @@ public function persistUntrackedEntityWithMatchingPkUpdates(): void
     #[Test]
     public function persistReadOnlyEntityInsertWorks(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('read_only_author', []);
 
         $entity = $mapper->entityFactory->create(Stubs\ReadOnlyAuthor::class, name: 'Alice');
@@ -781,7 +831,9 @@ public function persistReadOnlyEntityInsertWorks(): void
     #[Test]
     public function persistReadOnlyViaCollectionPkUpdates(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('read_only_author', [
             ['id' => 1, 'name' => 'Original', 'bio' => null],
         ]);
@@ -814,7 +866,9 @@ public function persistReadOnlyViaCollectionPkUpdates(): void
     #[Test]
     public function persistReadOnlyViaCollectionPkFlushUpdatesStorage(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('read_only_author', [
             ['id' => 1, 'name' => 'Original', 'bio' => null],
         ]);
@@ -835,7 +889,9 @@ public function persistReadOnlyViaCollectionPkFlushUpdatesStorage(): void
     #[Test]
     public function identityMapReplaceEvictsOldEntity(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('read_only_author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -853,7 +909,9 @@ public function identityMapReplaceEvictsOldEntity(): void
     #[Test]
     public function identityMapReplaceFallsBackToInsertWhenNoPkMatch(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('read_only_author', []);
 
         // No identity map entries — should insert
@@ -870,7 +928,9 @@ public function identityMapReplaceFallsBackToInsertWhenNoPkMatch(): void
     #[Test]
     public function identityMapReplaceDetachesPreviouslyPendingEntity(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Original'],
         ]);
@@ -897,7 +957,9 @@ public function identityMapReplaceDetachesPreviouslyPendingEntity(): void
     #[Test]
     public function identityMapReplaceSkipsSameEntity(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Test'],
         ]);
@@ -917,7 +979,9 @@ public function identityMapReplaceSkipsSameEntity(): void
     #[Test]
     public function readOnlyNestedHydrationWiresRelation(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('comment', [
             ['id' => 1, 'text' => 'Great post', 'post_id' => 5],
         ]);
@@ -939,7 +1003,9 @@ public function readOnlyNestedHydrationWiresRelation(): void
     #[Test]
     public function readOnlyNestedHydrationThreeLevels(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('comment', [
             ['id' => 1, 'text' => 'Nice', 'post_id' => 5],
         ]);
@@ -966,7 +1032,9 @@ public function readOnlyNestedHydrationThreeLevels(): void
     #[Test]
     public function readOnlyInsertWithRelationExtractsFk(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('post', []);
         $mapper->seed('author', []);
 
@@ -1000,7 +1068,9 @@ public function readOnlyInsertWithRelationExtractsFk(): void
     #[Test]
     public function readOnlyReplaceViaCollectionPkPreservesRelation(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Original', 'text' => 'Body', 'author_id' => 10],
         ]);
@@ -1035,7 +1105,9 @@ public function readOnlyReplaceViaCollectionPkPreservesRelation(): void
     #[Test]
     public function readOnlyReplaceWithNewRelation(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Original', 'text' => 'Body', 'author_id' => 10],
         ]);
@@ -1070,7 +1142,9 @@ public function readOnlyReplaceWithNewRelation(): void
     #[Test]
     public function partialEntityPersistAutoUpdatesViaIdentityMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Original', 'text' => 'Body', 'author_id' => 10],
         ]);
@@ -1097,7 +1171,9 @@ public function partialEntityPersistAutoUpdatesViaIdentityMap(): void
     #[Test]
     public function readOnlyMultipleEntitiesFetchAllTracksAll(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
             ['id' => 2, 'name' => 'Bob', 'bio' => null],
@@ -1125,7 +1201,9 @@ public function readOnlyMultipleEntitiesFetchAllTracksAll(): void
     #[Test]
     public function identityMapReplaceSkipsSetWhenPkAlreadyInitialized(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -1145,7 +1223,9 @@ public function identityMapReplaceSkipsSetWhenPkAlreadyInitialized(): void
     #[Test]
     public function persistReturnsEntity(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
 
         // Insert path
         $entity = new Stubs\Post();
@@ -1162,7 +1242,9 @@ public function persistReturnsEntity(): void
     #[Test]
     public function readOnlyDeleteEvictsFromIdentityMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -1184,7 +1266,9 @@ public function readOnlyDeleteEvictsFromIdentityMap(): void
     #[Test]
     public function persistPartialEntityOnPendingInsertMergesViaIdentityMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', []);
 
         $author = $mapper->entityFactory->create(Stubs\Immutable\Author::class, id: 1, name: 'Alice');
@@ -1203,7 +1287,9 @@ public function persistPartialEntityOnPendingInsertMergesViaIdentityMap(): void
     #[Test]
     public function persistPartialEntityOnTrackedUpdateMerges(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -1223,7 +1309,9 @@ public function persistPartialEntityOnTrackedUpdateMerges(): void
     #[Test]
     public function mutableMergeAppliesOverlayPropertiesToExisting(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -1250,7 +1338,9 @@ public function mutableMergeAppliesOverlayPropertiesToExisting(): void
     #[Test]
     public function readOnlyMergeNoDiffReturnsSameEntity(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -1269,7 +1359,9 @@ public function readOnlyMergeNoDiffReturnsSameEntity(): void
     #[Test]
     public function identityMapLookupNormalizesNumericStringCondition(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -1284,7 +1376,9 @@ public function identityMapLookupNormalizesNumericStringCondition(): void
     #[Test]
     public function identityMapLookupReturnsNullForNonScalarCondition(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -1299,7 +1393,9 @@ public function identityMapLookupReturnsNullForNonScalarCondition(): void
     #[Test]
     public function mutableMergeTracksExistingWhenNotYetTracked(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -1328,7 +1424,9 @@ public function mutableMergeTracksExistingWhenNotYetTracked(): void
     #[Test]
     public function mergeWithIdentityMapNormalizesConditionFallback(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
diff --git a/tests/Collections/CollectionTest.php b/tests/Collections/CollectionTest.php
index e1c417e..6dd39a6 100644
--- a/tests/Collections/CollectionTest.php
+++ b/tests/Collections/CollectionTest.php
@@ -328,18 +328,12 @@ public function magicGetShouldUseRegisteredCollectionFromMapper(): void
         $this->assertEquals('bar', $result->connectsTo?->name);
     }
 
-    #[Test]
-    public function hydrateFromSetsHydrator(): void
-    {
-        $hydrator = new Nested();
-        $coll = Collection::foo()->hydrateFrom($hydrator);
-        $this->assertSame($hydrator, $coll->hydrator);
-    }
-
     #[Test]
     public function persistReturnsSameEntity(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', []);
 
         $entity = $mapper->entityFactory->create(Stubs\Immutable\Author::class, name: 'Alice');
@@ -350,7 +344,9 @@ public function persistReturnsSameEntity(): void
     #[Test]
     public function persistPartialEntityMergesViaIdentityMap(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -369,7 +365,9 @@ public function persistPartialEntityMergesViaIdentityMap(): void
     #[Test]
     public function persistPartialEntityFlushesUpdate(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => null],
         ]);
@@ -389,7 +387,9 @@ public function persistPartialEntityFlushesUpdate(): void
     #[Test]
     public function persistPartialEntityOnGraphUpdatesRelation(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('post', [
             ['id' => 1, 'title' => 'Original', 'text' => 'Body', 'author_id' => 10],
         ]);
@@ -416,7 +416,9 @@ public function persistPartialEntityOnGraphUpdatesRelation(): void
     #[Test]
     public function persistPartialEntityNullValueApplied(): void
     {
-        $mapper = new InMemoryMapper(new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\'));
+        $mapper = new InMemoryMapper(new Nested(new EntityFactory(
+            entityNamespace: 'Respect\\Data\\Stubs\\Immutable\\',
+        )));
         $mapper->seed('author', [
             ['id' => 1, 'name' => 'Alice', 'bio' => 'has bio'],
         ]);
diff --git a/tests/Hydrators/NestedTest.php b/tests/Hydrators/NestedTest.php
index 7293f2c..ebf05aa 100644
--- a/tests/Hydrators/NestedTest.php
+++ b/tests/Hydrators/NestedTest.php
@@ -12,6 +12,7 @@
 use Respect\Data\EntityFactory;
 
 #[CoversClass(Nested::class)]
+#[CoversClass(Base::class)]
 class NestedTest extends TestCase
 {
     private Nested $hydrator;
@@ -20,8 +21,8 @@ class NestedTest extends TestCase
 
     protected function setUp(): void
     {
-        $this->hydrator = new Nested();
         $this->factory = new EntityFactory(entityNamespace: 'Respect\\Data\\Stubs\\');
+        $this->hydrator = new Nested($this->factory);
     }
 
     #[Test]
@@ -29,9 +30,9 @@ public function hydrateReturnsFalseForNonArray(): void
     {
         $collection = Collection::author();
 
-        $this->assertFalse($this->hydrator->hydrate(null, $collection, $this->factory));
-        $this->assertFalse($this->hydrator->hydrate(false, $collection, $this->factory));
-        $this->assertFalse($this->hydrator->hydrate('string', $collection, $this->factory));
+        $this->assertFalse($this->hydrator->hydrateAll(null, $collection));
+        $this->assertFalse($this->hydrator->hydrateAll(false, $collection));
+        $this->assertFalse($this->hydrator->hydrateAll('string', $collection));
     }
 
     #[Test]
@@ -40,7 +41,7 @@ public function hydrateSingleEntity(): void
         $raw = ['id' => 1, 'name' => 'Author Name'];
         $collection = Collection::author();
 
-        $result = $this->hydrator->hydrate($raw, $collection, $this->factory);
+        $result = $this->hydrator->hydrateAll($raw, $collection);
 
         $this->assertNotFalse($result);
         $this->assertCount(1, $result);
@@ -62,7 +63,7 @@ public function hydrateWithNestedChild(): void
         $collection = Collection::post();
         $collection->stack(Collection::author());
 
-        $result = $this->hydrator->hydrate($raw, $collection, $this->factory);
+        $result = $this->hydrator->hydrateAll($raw, $collection);
 
         $this->assertNotFalse($result);
         $this->assertCount(2, $result);
@@ -75,7 +76,7 @@ public function hydrateWithMissingNestedKeyReturnsPartial(): void
         $collection = Collection::post();
         $collection->stack(Collection::author());
 
-        $result = $this->hydrator->hydrate($raw, $collection, $this->factory);
+        $result = $this->hydrator->hydrateAll($raw, $collection);
 
         $this->assertNotFalse($result);
         $this->assertCount(1, $result);
@@ -98,7 +99,7 @@ public function hydrateDeeplyNested(): void
         $post->stack(Collection::author());
         $collection->stack($post);
 
-        $result = $this->hydrator->hydrate($raw, $collection, $this->factory);
+        $result = $this->hydrator->hydrateAll($raw, $collection);
 
         $this->assertNotFalse($result);
         $this->assertCount(3, $result);
@@ -117,7 +118,7 @@ public function hydrateWithChildren(): void
         $categoryColl = Collection::category();
         $collection = Collection::post($authorColl, $categoryColl);
 
-        $result = $this->hydrator->hydrate($raw, $collection, $this->factory);
+        $result = $this->hydrator->hydrateAll($raw, $collection);
 
         $this->assertNotFalse($result);
         $this->assertCount(3, $result);
@@ -129,7 +130,7 @@ public function hydrateWithTypedCollection(): void
         $raw = ['id' => 1, 'title' => 'Issue', 'type' => 'Bug'];
         $collection = Typed::issue('type');
 
-        $result = $this->hydrator->hydrate($raw, $collection, $this->factory);
+        $result = $this->hydrator->hydrateAll($raw, $collection);
 
         $this->assertNotFalse($result);
         $this->assertCount(1, $result);
@@ -143,7 +144,7 @@ public function hydrateChildWithNullNameIsSkipped(): void
         $collection = Collection::post();
         $collection->addChild($child);
 
-        $result = $this->hydrator->hydrate($raw, $collection, $this->factory);
+        $result = $this->hydrator->hydrateAll($raw, $collection);
 
         $this->assertNotFalse($result);
         $this->assertCount(1, $result);
@@ -156,9 +157,46 @@ public function hydrateScalarNestedValueIsIgnored(): void
         $collection = Collection::post();
         $collection->stack(Collection::author());
 
-        $result = $this->hydrator->hydrate($raw, $collection, $this->factory);
+        $result = $this->hydrator->hydrateAll($raw, $collection);
 
         $this->assertNotFalse($result);
         $this->assertCount(1, $result);
     }
+
+    #[Test]
+    public function hydrateReturnsFalseForInvalidInput(): void
+    {
+        $this->assertFalse($this->hydrator->hydrate(null, Collection::author()));
+    }
+
+    #[Test]
+    public function hydrateReturnsRootEntity(): void
+    {
+        $raw = ['id' => 1, 'name' => 'Alice'];
+        $result = $this->hydrator->hydrate($raw, Collection::author());
+
+        $this->assertNotFalse($result);
+        $this->assertEquals(1, $this->factory->get($result, 'id'));
+        $this->assertEquals('Alice', $this->factory->get($result, 'name'));
+    }
+
+    #[Test]
+    public function hydrateReturnsRootWithWiredRelation(): void
+    {
+        $raw = [
+            'id' => 1,
+            'title' => 'Post',
+            'author' => ['id' => 5, 'name' => 'Author'],
+        ];
+        $collection = Collection::post();
+        $collection->stack(Collection::author());
+
+        $result = $this->hydrator->hydrate($raw, $collection);
+
+        $this->assertNotFalse($result);
+        $this->assertEquals(1, $this->factory->get($result, 'id'));
+        $author = $this->factory->get($result, 'author');
+        $this->assertIsObject($author);
+        $this->assertEquals(5, $this->factory->get($author, 'id'));
+    }
 }
diff --git a/tests/Hydrators/PrestyledAssocTest.php b/tests/Hydrators/PrestyledAssocTest.php
index cda0014..0119e60 100644
--- a/tests/Hydrators/PrestyledAssocTest.php
+++ b/tests/Hydrators/PrestyledAssocTest.php
@@ -17,6 +17,7 @@
 use Respect\Data\Stubs\Bug;
 
 #[CoversClass(PrestyledAssoc::class)]
+#[CoversClass(Base::class)]
 class PrestyledAssocTest extends TestCase
 {
     private EntityFactory $factory;
@@ -29,24 +30,23 @@ protected function setUp(): void
     #[Test]
     public function hydrateReturnsFalseForEmpty(): void
     {
-        $hydrator = new PrestyledAssoc();
+        $hydrator = new PrestyledAssoc($this->factory);
         $coll = Collection::author();
 
-        $this->assertFalse($hydrator->hydrate(null, $coll, $this->factory));
-        $this->assertFalse($hydrator->hydrate([], $coll, $this->factory));
-        $this->assertFalse($hydrator->hydrate(false, $coll, $this->factory));
+        $this->assertFalse($hydrator->hydrateAll(null, $coll));
+        $this->assertFalse($hydrator->hydrateAll([], $coll));
+        $this->assertFalse($hydrator->hydrateAll(false, $coll));
     }
 
     #[Test]
     public function hydrateSingleEntity(): void
     {
-        $hydrator = new PrestyledAssoc();
+        $hydrator = new PrestyledAssoc($this->factory);
         $collection = Collection::author();
 
-        $result = $hydrator->hydrate(
+        $result = $hydrator->hydrateAll(
             ['author__id' => 1, 'author__name' => 'Alice'],
             $collection,
-            $this->factory,
         );
 
         $this->assertNotFalse($result);
@@ -60,10 +60,10 @@ public function hydrateSingleEntity(): void
     #[Test]
     public function hydrateMultipleEntitiesFromJoinedRow(): void
     {
-        $hydrator = new PrestyledAssoc();
+        $hydrator = new PrestyledAssoc($this->factory);
         $collection = Collection::author()->post;
 
-        $result = $hydrator->hydrate(
+        $result = $hydrator->hydrateAll(
             [
                 'author__id' => 1,
                 'author__name' => 'Alice',
@@ -72,7 +72,6 @@ public function hydrateMultipleEntitiesFromJoinedRow(): void
                 'post__author' => 1,
             ],
             $collection,
-            $this->factory,
         );
 
         $this->assertNotFalse($result);
@@ -92,10 +91,10 @@ public function hydrateMultipleEntitiesFromJoinedRow(): void
     #[Test]
     public function hydrateWiresRelationships(): void
     {
-        $hydrator = new PrestyledAssoc();
+        $hydrator = new PrestyledAssoc($this->factory);
         $collection = Collection::post()->author;
 
-        $result = $hydrator->hydrate(
+        $result = $hydrator->hydrateAll(
             [
                 'post__id' => 10,
                 'post__title' => 'Hello',
@@ -104,7 +103,6 @@ public function hydrateWiresRelationships(): void
                 'author__name' => 'Alice',
             ],
             $collection,
-            $this->factory,
         );
 
         $this->assertNotFalse($result);
@@ -115,16 +113,38 @@ public function hydrateWiresRelationships(): void
         $this->assertEquals(1, $this->factory->get($author, 'id'));
     }
 
+    #[Test]
+    public function hydrateReturnsRootRegardlessOfColumnOrder(): void
+    {
+        $hydrator = new PrestyledAssoc($this->factory);
+        $collection = Collection::post()->author;
+
+        // Author columns appear before post columns
+        $result = $hydrator->hydrate(
+            [
+                'author__id' => 1,
+                'author__name' => 'Alice',
+                'post__id' => 10,
+                'post__title' => 'Hello',
+                'post__author' => 1,
+            ],
+            $collection,
+        );
+
+        $this->assertNotFalse($result);
+        $this->assertEquals(10, $this->factory->get($result, 'id'));
+        $this->assertEquals('Hello', $this->factory->get($result, 'title'));
+    }
+
     #[Test]
     public function hydrateResolvesTypedEntities(): void
     {
-        $hydrator = new PrestyledAssoc();
+        $hydrator = new PrestyledAssoc($this->factory);
         $collection = Typed::issue('type');
 
-        $result = $hydrator->hydrate(
+        $result = $hydrator->hydrateAll(
             ['issue__id' => 1, 'issue__type' => 'Bug', 'issue__title' => 'Bug Report'],
             $collection,
-            $this->factory,
         );
 
         $this->assertNotFalse($result);
@@ -135,15 +155,14 @@ public function hydrateResolvesTypedEntities(): void
     #[Test]
     public function hydrateSkipsUnfilteredFilteredCollections(): void
     {
-        $hydrator = new PrestyledAssoc();
+        $hydrator = new PrestyledAssoc($this->factory);
         $filtered = Filtered::post();
         $collection = Collection::author();
         $collection->stack($filtered);
 
-        $result = $hydrator->hydrate(
+        $result = $hydrator->hydrateAll(
             ['author__id' => 1, 'author__name' => 'Alice'],
             $collection,
-            $this->factory,
         );
 
         $this->assertNotFalse($result);
@@ -153,10 +172,10 @@ public function hydrateSkipsUnfilteredFilteredCollections(): void
     #[Test]
     public function hydrateCompositeEntity(): void
     {
-        $hydrator = new PrestyledAssoc();
+        $hydrator = new PrestyledAssoc($this->factory);
         $composite = Composite::author(['profile' => ['bio']])->post;
 
-        $result = $hydrator->hydrate(
+        $result = $hydrator->hydrateAll(
             [
                 'author__id' => 1,
                 'author__name' => 'Alice',
@@ -165,7 +184,6 @@ public function hydrateCompositeEntity(): void
                 'post__title' => 'Hello',
             ],
             $composite,
-            $this->factory,
         );
 
         $this->assertNotFalse($result);
@@ -179,18 +197,16 @@ public function hydrateCompositeEntity(): void
     #[Test]
     public function hydrateCachesCollMapAcrossRows(): void
     {
-        $hydrator = new PrestyledAssoc();
+        $hydrator = new PrestyledAssoc($this->factory);
         $collection = Collection::author();
 
-        $first = $hydrator->hydrate(
+        $first = $hydrator->hydrateAll(
             ['author__id' => 1, 'author__name' => 'Alice'],
             $collection,
-            $this->factory,
         );
-        $second = $hydrator->hydrate(
+        $second = $hydrator->hydrateAll(
             ['author__id' => 2, 'author__name' => 'Bob'],
             $collection,
-            $this->factory,
         );
 
         $this->assertNotFalse($first);
@@ -200,15 +216,14 @@ public function hydrateCachesCollMapAcrossRows(): void
     #[Test]
     public function hydrateThrowsOnUnknownPrefix(): void
     {
-        $hydrator = new PrestyledAssoc();
+        $hydrator = new PrestyledAssoc($this->factory);
         $collection = Collection::author();
 
         $this->expectException(DomainException::class);
         $this->expectExceptionMessage('Unknown column prefix');
-        $hydrator->hydrate(
+        $hydrator->hydrateAll(
             ['author__id' => 1, 'unknown__foo' => 'bar'],
             $collection,
-            $this->factory,
         );
     }
 }
diff --git a/tests/InMemoryMapper.php b/tests/InMemoryMapper.php
index 9620599..b73dce7 100644
--- a/tests/InMemoryMapper.php
+++ b/tests/InMemoryMapper.php
@@ -5,7 +5,6 @@
 namespace Respect\Data;
 
 use Respect\Data\Collections\Collection;
-use Respect\Data\Hydrators\Nested;
 
 use function array_filter;
 use function array_merge;
@@ -83,11 +82,6 @@ public function flush(): void
         $this->reset();
     }
 
-    protected function defaultHydrator(Collection $collection): Hydrator
-    {
-        return new Nested();
-    }
-
     private function insertEntity(object $entity, Collection $collection, string $tableName, string $id): void
     {
         $row = $this->filterColumns(
@@ -143,7 +137,7 @@ private function hydrateRow(array $row, Collection $collection): object|false
     {
         $this->attachRelated($row, $collection);
 
-        $entities = $this->resolveHydrator($collection)->hydrate($row, $collection, $this->entityFactory);
+        $entities = $this->hydrator->hydrateAll($row, $collection);
         if ($entities === false) {
             return false;
         }
diff --git a/tests/Styles/CakePHP/CakePHPIntegrationTest.php b/tests/Styles/CakePHP/CakePHPIntegrationTest.php
index e99b40a..bb238ed 100644
--- a/tests/Styles/CakePHP/CakePHPIntegrationTest.php
+++ b/tests/Styles/CakePHP/CakePHPIntegrationTest.php
@@ -7,6 +7,7 @@
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\TestCase;
 use Respect\Data\EntityFactory;
+use Respect\Data\Hydrators\Nested;
 use Respect\Data\InMemoryMapper;
 use Respect\Data\Styles\CakePHP;
 
@@ -20,10 +21,10 @@ class CakePHPIntegrationTest extends TestCase
     protected function setUp(): void
     {
         $this->style = new CakePHP();
-        $this->mapper = new InMemoryMapper(new EntityFactory(
+        $this->mapper = new InMemoryMapper(new Nested(new EntityFactory(
             style: $this->style,
             entityNamespace: __NAMESPACE__ . '\\',
-        ));
+        )));
 
         $this->mapper->seed('posts', [
             ['id' => 5, 'title' => 'Post Title', 'text' => 'Post Text', 'author_id' => 1],
diff --git a/tests/Styles/NorthWind/NorthWindIntegrationTest.php b/tests/Styles/NorthWind/NorthWindIntegrationTest.php
index bf440e7..bb3b4c3 100644
--- a/tests/Styles/NorthWind/NorthWindIntegrationTest.php
+++ b/tests/Styles/NorthWind/NorthWindIntegrationTest.php
@@ -7,6 +7,7 @@
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\TestCase;
 use Respect\Data\EntityFactory;
+use Respect\Data\Hydrators\Nested;
 use Respect\Data\InMemoryMapper;
 use Respect\Data\Styles\NorthWind;
 
@@ -20,10 +21,10 @@ class NorthWindIntegrationTest extends TestCase
     protected function setUp(): void
     {
         $this->style = new NorthWind();
-        $this->mapper = new InMemoryMapper(new EntityFactory(
+        $this->mapper = new InMemoryMapper(new Nested(new EntityFactory(
             style: $this->style,
             entityNamespace: __NAMESPACE__ . '\\',
-        ));
+        )));
 
         $this->mapper->seed('Posts', [
             ['PostID' => 5, 'Title' => 'Post Title', 'Text' => 'Post Text', 'AuthorID' => 1],
diff --git a/tests/Styles/Plural/PluralIntegrationTest.php b/tests/Styles/Plural/PluralIntegrationTest.php
index f60fab4..ce88fa7 100644
--- a/tests/Styles/Plural/PluralIntegrationTest.php
+++ b/tests/Styles/Plural/PluralIntegrationTest.php
@@ -7,6 +7,7 @@
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\TestCase;
 use Respect\Data\EntityFactory;
+use Respect\Data\Hydrators\Nested;
 use Respect\Data\InMemoryMapper;
 use Respect\Data\Styles\Plural;
 
@@ -20,10 +21,10 @@ class PluralIntegrationTest extends TestCase
     protected function setUp(): void
     {
         $this->style = new Plural();
-        $this->mapper = new InMemoryMapper(new EntityFactory(
+        $this->mapper = new InMemoryMapper(new Nested(new EntityFactory(
             style: $this->style,
             entityNamespace: __NAMESPACE__ . '\\',
-        ));
+        )));
 
         $this->mapper->seed('posts', [
             ['id' => 5, 'title' => 'Post Title', 'text' => 'Post Text', 'author_id' => 1],
diff --git a/tests/Styles/Sakila/SakilaIntegrationTest.php b/tests/Styles/Sakila/SakilaIntegrationTest.php
index 5129a4d..d06c550 100644
--- a/tests/Styles/Sakila/SakilaIntegrationTest.php
+++ b/tests/Styles/Sakila/SakilaIntegrationTest.php
@@ -7,6 +7,7 @@
 use PHPUnit\Framework\Attributes\CoversClass;
 use PHPUnit\Framework\TestCase;
 use Respect\Data\EntityFactory;
+use Respect\Data\Hydrators\Nested;
 use Respect\Data\InMemoryMapper;
 use Respect\Data\Styles\Sakila;
 
@@ -20,10 +21,10 @@ class SakilaIntegrationTest extends TestCase
     protected function setUp(): void
     {
         $this->style = new Sakila();
-        $this->mapper = new InMemoryMapper(new EntityFactory(
+        $this->mapper = new InMemoryMapper(new Nested(new EntityFactory(
             style: $this->style,
             entityNamespace: __NAMESPACE__ . '\\',
-        ));
+        )));
 
         $this->mapper->seed('post', [
             ['post_id' => 5, 'title' => 'Post Title', 'text' => 'Post Text', 'author_id' => 1],