diff --git a/src/AcDream.App/Rendering/GameWindow.cs b/src/AcDream.App/Rendering/GameWindow.cs
index 8910e919..e4f61dc3 100644
--- a/src/AcDream.App/Rendering/GameWindow.cs
+++ b/src/AcDream.App/Rendering/GameWindow.cs
@@ -2394,6 +2394,7 @@ public sealed class GameWindow : IDisposable
             _vitalsVm?.SetLocalPlayerGuid(chosen.Id);
             Chat.SetLocalPlayerGuid(chosen.Id);
             _worldState.MarkPersistent(chosen.Id);
+            AcDream.App.Streaming.EntityVanishProbe.PlayerGuid = chosen.Id;  // TEMP #138-B probe
             Console.WriteLine($"live: entering world as 0x{chosen.Id:X8} {chosen.Name}");
             _liveSession.EnterWorld(user, characterIndex: 0);
 
@@ -8014,7 +8015,21 @@ public sealed class GameWindow : IDisposable
                     int ply = _liveCenterY + (int)System.Math.Floor(pp.Y / 192f);
                     currentLb = (uint)((plx << 24) | (ply << 16) | 0xFFFF);
                 }
-                _worldState.RelocateEntity(pe, currentLb);
+                // #138-B (2026-06-24): do NOT relocate the avatar while a teleport
+                // is in transit (PortalSpace). The controller's cell is still the
+                // FROZEN SOURCE until PlaceTeleportArrival materializes the
+                // destination, so relocating here drags the avatar — which the
+                // teleport's rescue/re-inject (GpuWorldState.DrainRescued) already
+                // placed at the destination center — back into the now-UNLOADED
+                // SOURCE landblock's pending bucket, where nothing recovers it
+                // (RelocateEntity only scans _loaded). Net: the avatar vanishes
+                // after teleporting out. The teleport machinery owns the avatar's
+                // landblock during transit; per-frame relocation resumes at
+                // FireLoginComplete (InWorld). Probe-confirmed: launch4 line 561
+                // APPEND guid=player lb=0x0007FFFF(source dungeon) -> PENDING ->
+                // DRAWSET ABSENT, never recovered.
+                if (_playerController.State != AcDream.App.Input.PlayerState.PortalSpace)
+                    _worldState.RelocateEntity(pe, currentLb);
             }
 
             // Update chase camera(s). The CameraController exposes whichever
diff --git a/src/AcDream.App/Rendering/RetailPViewRenderer.cs b/src/AcDream.App/Rendering/RetailPViewRenderer.cs
index 2819c3c5..30db299f 100644
--- a/src/AcDream.App/Rendering/RetailPViewRenderer.cs
+++ b/src/AcDream.App/Rendering/RetailPViewRenderer.cs
@@ -726,6 +726,10 @@ public sealed class RetailPViewRenderer
         {
             EntitySphere(e, out var c, out float r);
             bool indoor = InteriorEntityPartition.IsIndoorCellId(e.ParentCellId);
+            // TEMP (#138-B): trace the avatar's survival through this cull.
+            bool isProbePlayer = AcDream.App.Streaming.EntityVanishProbe.Enabled
+                && AcDream.App.Streaming.EntityVanishProbe.PlayerGuid != 0
+                && e.ServerGuid == AcDream.App.Streaming.EntityVanishProbe.PlayerGuid;
             // #118: under an interior root, outdoor-classified dynamics drew in
             // the outside stage (pre-clear, seal-protected) — retail draws them
             // via LScape::draw's per-landcell DrawSortCell, never in the
@@ -734,10 +738,18 @@ public sealed class RetailPViewRenderer
             // seal. Indoor dynamics (incl. exit-portal straddlers, which drew
             // in BOTH stages) stay — this pass is retail's loop C.
             if (!rootIsOutdoor && !indoor)
+            {
+                if (isProbePlayer)
+                    AcDream.App.Streaming.EntityVanishProbe.LogPlayerDynOnChange(
+                        $"cell=0x{(e.ParentCellId ?? 0):X8} indoor=False rootOutdoor={rootIsOutdoor} -> CULLED(outside-stage)");
                 continue;
+            }
             bool visible = indoor
                 ? viewcone.SphereVisibleInCell(e.ParentCellId!.Value, c, r)
                 : viewcone.SphereVisibleOutside(c, r);
+            if (isProbePlayer)
+                AcDream.App.Streaming.EntityVanishProbe.LogPlayerDynOnChange(
+                    $"cell=0x{(e.ParentCellId ?? 0):X8} indoor={indoor} rootOutdoor={rootIsOutdoor} viewcone={visible} -> {(visible ? "DRAWN" : "CULLED(viewcone)")}");
             if (visible)
                 _dynamicsScratch.Add(e);
         }
diff --git a/src/AcDream.App/Streaming/EntityVanishProbe.cs b/src/AcDream.App/Streaming/EntityVanishProbe.cs
new file mode 100644
index 00000000..a991e261
--- /dev/null
+++ b/src/AcDream.App/Streaming/EntityVanishProbe.cs
@@ -0,0 +1,49 @@
+using System;
+
+namespace AcDream.App.Streaming;
+
+/// <summary>
+/// TEMP diagnostic (#138-B avatar-vanish). Env-gated (<c>ACDREAM_PROBE_ENT=1</c>)
+/// trace of the persistent player entity across teleport streaming churn:
+/// whether it is present in the render draw-DATA (<see cref="GpuWorldState"/>
+/// flat view) and whether it survives the dynamics CULL
+/// (<c>RetailPViewRenderer.DrawDynamicsLast</c>).
+///
+/// <para>The two halves answer the decisive question: is the avatar
+/// "missing for a moment" because it is <b>absent from the draw set</b>
+/// (re-injected into the pending bucket while its landblock re-streams), or
+/// because it is <b>present but culled</b> (in the dynamics list, dropped by
+/// the outside-stage / viewcone gate)?</para>
+///
+/// <para>STRIP once #138-B is root-caused (throwaway, like the dense-town FPS
+/// apparatus). Observation-only — emits no behavior change.</para>
+/// </summary>
+internal static class EntityVanishProbe
+{
+    public static readonly bool Enabled =
+        Environment.GetEnvironmentVariable("ACDREAM_PROBE_ENT") == "1";
+
+    /// <summary>Player server guid, set once at world entry so the draw-side
+    /// <c>[dyn]</c> line can single out the avatar without plumbing the guid
+    /// through the render stack.</summary>
+    public static uint PlayerGuid;
+
+    public static void Log(string msg)
+    {
+        if (Enabled) Console.WriteLine(msg);
+    }
+
+    private static string _lastPlayerDyn = "";
+
+    /// <summary>Emit a <c>[dyn] player</c> line only when the outcome string
+    /// changes — a stationary, drawn avatar must not spam one line per frame
+    /// (that console+Tee I/O would itself depress FPS and bury the signal).
+    /// Fires on cell change or DRAWN↔CULLED transition.</summary>
+    public static void LogPlayerDynOnChange(string status)
+    {
+        if (!Enabled) return;
+        if (status == _lastPlayerDyn) return;
+        _lastPlayerDyn = status;
+        Console.WriteLine("[dyn] player " + status);
+    }
+}
diff --git a/src/AcDream.App/Streaming/GpuWorldState.cs b/src/AcDream.App/Streaming/GpuWorldState.cs
index 5f67b527..6217c814 100644
--- a/src/AcDream.App/Streaming/GpuWorldState.cs
+++ b/src/AcDream.App/Streaming/GpuWorldState.cs
@@ -298,6 +298,7 @@ public sealed class GpuWorldState
                 if (entity.ServerGuid != 0 && _persistentGuids.Contains(entity.ServerGuid))
                 {
                     _persistentRescued.Add(entity);
+                    EntityVanishProbe.Log($"[ent] RESCUE guid=0x{entity.ServerGuid:X8} from=loaded lb=0x{landblockId:X8}");
                 }
             }
 
@@ -331,7 +332,10 @@ public sealed class GpuWorldState
             foreach (var entity in pendingForLb)
             {
                 if (entity.ServerGuid != 0 && _persistentGuids.Contains(entity.ServerGuid))
+                {
                     _persistentRescued.Add(entity);
+                    EntityVanishProbe.Log($"[ent] RESCUE guid=0x{entity.ServerGuid:X8} from=pending lb=0x{landblockId:X8}");
+                }
             }
         }
 
@@ -439,6 +443,8 @@ public sealed class GpuWorldState
         _entityScriptActivator?.OnCreate(entity);
 
         uint canonicalLandblockId = (landblockId & 0xFFFF0000u) | 0xFFFFu;
+        bool probePersistent = EntityVanishProbe.Enabled
+            && entity.ServerGuid != 0 && _persistentGuids.Contains(entity.ServerGuid);
 
         if (_loaded.TryGetValue(canonicalLandblockId, out var lb))
         {
@@ -451,6 +457,8 @@ public sealed class GpuWorldState
                 lb.LandblockId,
                 lb.Heightmap,
                 newEntities);
+            if (probePersistent)
+                EntityVanishProbe.Log($"[ent] APPEND guid=0x{entity.ServerGuid:X8} lb=0x{canonicalLandblockId:X8} -> LOADED(drawn)");
             RebuildFlatView();
             return;
         }
@@ -464,6 +472,8 @@ public sealed class GpuWorldState
             _pendingByLandblock[canonicalLandblockId] = bucket;
         }
         bucket.Add(entity);
+        if (probePersistent)
+            EntityVanishProbe.Log($"[ent] APPEND guid=0x{entity.ServerGuid:X8} lb=0x{canonicalLandblockId:X8} -> PENDING(hidden)");
     }
 
     /// <summary>
@@ -570,5 +580,29 @@ public sealed class GpuWorldState
     private void RebuildFlatView()
     {
         _flatEntities = _loaded.Values.SelectMany(lb => lb.Entities).ToArray();
+        if (EntityVanishProbe.Enabled) ProbeFlatViewTransitions();
+    }
+
+    // TEMP (#138-B): persistent guids currently present in the drawn flat
+    // view, for EntityVanishProbe transition logging. Strip with the probe.
+    private readonly HashSet<uint> _persistentInFlatProbe = new();
+
+    // TEMP (#138-B): log when a persistent (player) entity enters/leaves the
+    // drawn flat view. Transition-gated → low volume (fires at teleport
+    // boundaries, not every rebuild). Strip with EntityVanishProbe.
+    private void ProbeFlatViewTransitions()
+    {
+        var now = new HashSet<uint>();
+        foreach (var e in _flatEntities)
+            if (e.ServerGuid != 0 && _persistentGuids.Contains(e.ServerGuid))
+                now.Add(e.ServerGuid);
+        foreach (var g in now)
+            if (!_persistentInFlatProbe.Contains(g))
+                EntityVanishProbe.Log($"[ent] DRAWSET guid=0x{g:X8} -> PRESENT (flatCount={_flatEntities.Count})");
+        foreach (var g in _persistentInFlatProbe)
+            if (!now.Contains(g))
+                EntityVanishProbe.Log($"[ent] DRAWSET guid=0x{g:X8} -> ABSENT (flatCount={_flatEntities.Count})");
+        _persistentInFlatProbe.Clear();
+        foreach (var g in now) _persistentInFlatProbe.Add(g);
     }
 }