diff --git a/packages/data-layer/src/monitor_data/tools/mongodb_tools.py b/packages/data-layer/src/monitor_data/tools/mongodb_tools.py
index e995ffc2..770354eb 100644
--- a/packages/data-layer/src/monitor_data/tools/mongodb_tools.py
+++ b/packages/data-layer/src/monitor_data/tools/mongodb_tools.py
@@ -1266,13 +1266,13 @@ def mongodb_create_combat(params: CombatCreate) -> CombatResponse:
         raise ValueError(f"Scene {params.scene_id} not found")
 
     # Validate story exists (via Neo4j)
-    neo4j = get_neo4j_client()
-    with neo4j.session() as session:  # type: ignore[attr-defined]
-        result = session.run(
-            "MATCH (s:Story {id: $story_id}) RETURN s", story_id=str(params.story_id)
-        )
-        if not result.single():
-            raise ValueError(f"Story {params.story_id} not found")
+    neo4j_client = get_neo4j_client()
+    story_exists = neo4j_client.execute_read(
+        "MATCH (s:Story {id: $story_id}) RETURN s.id AS story_id",
+        {"story_id": str(params.story_id)},
+    )
+    if not story_exists:
+        raise ValueError(f"Story {params.story_id} not found")
 
     now = datetime.now(timezone.utc)
     encounter_id = uuid4()
diff --git a/packages/data-layer/tests/test_tools/test_combat_tools.py b/packages/data-layer/tests/test_tools/test_combat_tools.py
index e727163f..fda83191 100644
--- a/packages/data-layer/tests/test_tools/test_combat_tools.py
+++ b/packages/data-layer/tests/test_tools/test_combat_tools.py
@@ -71,14 +71,8 @@ def test_create_combat_success(
 
     # Mock Neo4j
     mock_neo4j = MagicMock()
-    mock_session = MagicMock()
-    mock_result = MagicMock()
-    mock_single = MagicMock()
-
     mock_get_neo4j.return_value = mock_neo4j
-    mock_neo4j.session.return_value.__enter__.return_value = mock_session
-    mock_session.run.return_value = mock_result
-    mock_result.single.return_value = mock_single
+    mock_neo4j.execute_read.return_value = [{"story_id": str(story_id)}]
 
     # Test data
     participants = [
@@ -146,6 +140,38 @@ def test_create_combat_scene_not_found(
         mongodb_create_combat(params)
 
 
+@patch("monitor_data.tools.mongodb_tools.get_neo4j_client")
+@patch("monitor_data.tools.mongodb_tools.get_mongodb_client")
+def test_create_combat_story_not_found(
+    mock_get_mongodb: Mock,
+    mock_get_neo4j: Mock,
+):
+    """Test creating combat with invalid story_id."""
+    scene_id = uuid4()
+    story_id = uuid4()
+
+    mock_mongodb = MagicMock()
+    mock_combats = MagicMock()
+    mock_scenes = MagicMock()
+
+    mock_get_mongodb.return_value = mock_mongodb
+    mock_mongodb.get_collection.side_effect = lambda name: (
+        mock_combats if name == "combat_encounters" else mock_scenes
+    )
+
+    # Scene exists but story does not
+    mock_scenes.find_one.return_value = {"scene_id": str(scene_id)}
+    mock_get_neo4j.return_value = MagicMock(execute_read=MagicMock(return_value=[]))
+
+    params = CombatCreate(
+        scene_id=scene_id,
+        story_id=story_id,
+    )
+
+    with pytest.raises(ValueError, match=f"Story {story_id} not found"):
+        mongodb_create_combat(params)
+
+
 # =============================================================================
 # TEST: mongodb_get_combat
 # =============================================================================