diff --git a/Controls/TopBar.xaml b/Controls/TopBar.xaml
index e4e8cc0..63512b9 100644
--- a/Controls/TopBar.xaml
+++ b/Controls/TopBar.xaml
@@ -67,7 +67,8 @@
                  highlighted half re-enters it, which is how a creator gets back to the layers
                  during a session. -->
             <Border Background="{StaticResource Brush.SurfaceContainerLowest}" CornerRadius="4"
-                    Padding="2" Height="32" VerticalAlignment="Center" Margin="0,0,12,0">
+                    Padding="2" Height="32" VerticalAlignment="Center" Margin="0,0,12,0"
+                    Visibility="{Binding IsBuildWorld, Converter={StaticResource BoolToVis}}">
                 <StackPanel Orientation="Horizontal">
                     <!-- Build Scenes carries a LAYOUT glyph while it is the active world and a PADLOCK
                          once Record / Go Live is: the door is still there, it is just behind the
@@ -81,10 +82,7 @@
                                   Fill="{Binding Foreground, RelativeSource={RelativeSource AncestorType=Button}}"
                                   Visibility="{Binding IsBuildWorld, Converter={StaticResource BoolToVis}}"
                                   Data="M3,4h8v6H3V4zM13,4h8v6h-8V4zM3,12h8v8H3V12zM13,12h8v8h-8V12z"/>
-                            <Path Width="14" Height="14" Stretch="Uniform" VerticalAlignment="Center"
-                                  Fill="{Binding Foreground, RelativeSource={RelativeSource AncestorType=Button}}"
-                                  Visibility="{Binding IsOutputWorld, Converter={StaticResource BoolToVis}}"
-                                  Data="M7,10V7a5,5 0 0,1 10,0v3h1a1,1 0 0,1 1,1v9a1,1 0 0,1 -1,1H6a1,1 0 0,1 -1,-1v-9a1,1 0 0,1 1,-1h1zM9,10h6V7a3,3 0 0,0 -6,0v3z"/>
+
                             <TextBlock Text="Build Scenes" FontSize="12" FontWeight="Bold" Margin="6,0,0,0"
                                        VerticalAlignment="Center"
                                        Foreground="{Binding Foreground, RelativeSource={RelativeSource AncestorType=Button}}"/>
@@ -109,6 +107,17 @@
             <!-- IDLE: the mode switch + the action(s) of the armed world. The three
                  controls share one height (build 77 feedback) so they read as one
                  family — segments host, Start/Go Live, and Test all sit at 32. -->
+            <!-- The Output world REPLACES the segment (creator ruling 2026-11-12): choosing Record / Go
+                 Live takes the dual button away and puts the output line in its place. This chevron is
+                 the way back to Build Scenes — present for the whole world, running or not, so editing
+                 during a show (unit 1) still has an entry point and the bar has no dead end. -->
+            <Button Style="{StaticResource IconButton}" Width="28" Height="32" Margin="0,0,6,0"
+                    Command="{Binding EnterBuildWorldCommand}" ToolTip="Back to Build Scenes"
+                    Visibility="{Binding IsOutputWorld, Converter={StaticResource BoolToVis}}">
+                <Path Data="M15.41,7.41L14,6l-6,6 6,6 1.41,-1.41L10.83,12z" Width="14" Height="14"
+                      Stretch="Uniform" Fill="{StaticResource Brush.OnSurface}"
+                      HorizontalAlignment="Center" VerticalAlignment="Center"/>
+            </Button>
             <!-- THE OUTPUT STAGE (creator ruling 2026-11-12): which single output, and the one action
                  that starts it. Appears only in the Record / Go Live world and only while nothing is
                  running — a live session cannot change its output. YouTube and Local MP4 are one axis,
diff --git a/docs/ai/ui-surface.md b/docs/ai/ui-surface.md
index ab5808e..4c1440d 100644
--- a/docs/ai/ui-surface.md
+++ b/docs/ai/ui-surface.md
@@ -151,7 +151,10 @@ Placement math itself is covered by `WindowPlacementTests` (pure function, no HW
   leads the centre cluster and stays present in every state; clicking the highlighted half re-enters it,
   which is how a creator gets back to the layers during a session. `WorldSegmentButton`
   (`Themes/Controls.xaml`) is a Button, not a ToggleButton — the highlight follows the view model, and a
-  click must never be what sets it.
+  click must never be what sets it. The segment exists **only** in the Build world: choosing Record / Go
+  Live **replaces** it with the output line, and a left chevron (`Back to Build Scenes`) is present for
+  the whole Output world, running included — the way back to the layers, and the reason the bar has no
+  dead end.
 - **The output stage** (`ShowOutputStage`) is the idle cluster and lives only in the Record / Go Live
   world while nothing runs: `Output [▶ YouTube] [● Local MP4] One output at a time`, each switch carrying
   its glyph, with **Local MP4 armed at launch** (`RecordPillOn` starts true — it did not before). The two
diff --git a/ytLive.Tests/UiShellTests.cs b/ytLive.Tests/UiShellTests.cs
index fce11d6..ec8c84b 100644
--- a/ytLive.Tests/UiShellTests.cs
+++ b/ytLive.Tests/UiShellTests.cs
@@ -35,11 +35,11 @@ public class UiShellTests
         Assert.Contains("Tag=\"{Binding IsOutputWorld}\"", topBar);
         Assert.DoesNotContain("x:Name=\"EditBody\"", topBar);
 
-        // 2b. Build Scenes carries a layout glyph while it is the active world, and a padlock once
-        //     Record / Go Live is — each lit by its own world flag (creator ruling 2026-11-12).
+        // 2b. The segment is Build-world only: choosing Record / Go Live REPLACES it with the output
+        //     line (creator ruling 2026-11-12), and a chevron is the way back.
         Assert.Contains("Data=\"M3,4h8v6H3V4zM13,4h8v6h-8V4zM3,12h8v8H3V12zM13,12h8v8h-8V12z\"", topBar);
-        Assert.Contains("Data=\"M7,10V7a5,5 0 0,1 10,0v3h1", topBar);
-        Assert.Contains("Visibility=\"{Binding IsOutputWorld, Converter={StaticResource BoolToVis}}\"", topBar);
+        Assert.Contains("Visibility=\"{Binding IsBuildWorld, Converter={StaticResource BoolToVis}}\"", topBar);
+        Assert.Contains("ToolTip=\"Back to Build Scenes\"", topBar);
 
         // 2c. The output stage: two labelled switches and the exclusivity promise beside them.
         Assert.Contains("Text=\"Output\"", topBar);