diff --git a/Assets/_Project/Scripts/Simulation/Player/CharacterProcessor.cs b/Assets/_Project/Scripts/Simulation/Player/CharacterProcessor.cs
index 08b867f31..3862b41d4 100644
--- a/Assets/_Project/Scripts/Simulation/Player/CharacterProcessor.cs
+++ b/Assets/_Project/Scripts/Simulation/Player/CharacterProcessor.cs
@@ -34,6 +34,7 @@ namespace ProjectM.Simulation
             ref CharacterComponent characterComponent = ref CharacterComponent.ValueRW;
             ref KinematicCharacterBody characterBody = ref CharacterDataAccess.CharacterBody.ValueRW;
             ref float3 characterPosition = ref CharacterDataAccess.LocalTransform.ValueRW.Position;
+            float planeY = characterPosition.y; // authored movement plane — restored after the update (see below)
 
             KinematicCharacterUtilities.Update_Initialize(
                 in this, ref context, ref baseContext,
@@ -100,6 +101,14 @@ namespace ProjectM.Simulation
             KinematicCharacterUtilities.Update_ProcessStatefulCharacterHits(
                 CharacterDataAccess.CharacterHitsBuffer,
                 CharacterDataAccess.StatefulHitsBuffer);
+
+            // Top-down planar lock: the world is one flat plane and gravity is zero, so any Y gained by
+            // step-handling/velocity-projection up a sloped collider (convex rock hulls etc.) would persist
+            // FOREVER — the character ends up floating and its shadow drifts away (07-09 field report).
+            // Restoring the pre-update Y forbids the CC update itself from ever changing the plane while
+            // spawn/teleport writes (made outside this update) stay honored. Deterministic + idempotent.
+            characterPosition.y = planeY;
+            characterBody.RelativeVelocity.y = 0f;
         }
 
         void HandleVelocityControl(ref CharacterUpdateContext context, ref KinematicCharacterUpdateContext baseContext)