diff --git a/src/AcDream.App/UI/Layout/ChatWindowController.cs b/src/AcDream.App/UI/Layout/ChatWindowController.cs
index ccdf8f7b..777739d5 100644
--- a/src/AcDream.App/UI/Layout/ChatWindowController.cs
+++ b/src/AcDream.App/UI/Layout/ChatWindowController.cs
@@ -52,6 +52,13 @@ public sealed class ChatWindowController : IRetainedWindowStateController, IReta
     private const uint RootId         = 0x10000600u;   // gmFloatyMainChatUI window root, 410x100
     private const uint TranscriptPanelId = 0x10000010u;
     private const uint TranscriptId   = 0x10000011u;   // Type-12 prototype — skipped by factory
+
+    /// <summary>
+    /// Retail's "there is new text you have not seen" indicator, shown only
+    /// while the transcript is scrolled off the bottom
+    /// (<c>ChatInterface::ListenToElementMessage @0x004F51C0</c>).
+    /// </summary>
+    private const uint UnreadIndicatorId = 0x1000048Cu;
     private const uint TrackId        = 0x10000012u;
     private const uint InputBarId     = 0x10000013u;
     private const uint MenuId         = 0x10000014u;
@@ -143,6 +150,14 @@ public sealed class ChatWindowController : IRetainedWindowStateController, IReta
     /// </summary>
     private readonly List<IReadOnlyList<(int Start, int Length, ChatTextTag Tag)>?>
         _cachedTranscriptTags = new();
+
+    private UiElement? _unreadIndicator;
+
+    /// <summary>
+    /// Set when a line arrives while the transcript is scrolled up, cleared
+    /// the moment the view is back at the bottom.
+    /// </summary>
+    private bool _hasUnseenText;
     private long _cachedTranscriptRevision = -1;
     private ulong _cachedFilter;
     private float _cachedTranscriptWrapWidth = float.NaN;
@@ -353,6 +368,15 @@ public sealed class ChatWindowController : IRetainedWindowStateController, IReta
         // @0x004CCE10 -> ChatInterface::StartTell @0x004F41F0.
         c.Transcript.OnCharClick = pos => c.TryStartTellFromTag(pos);
 
+        // ── Unread indicator ─────────────────────────────────────────────
+        c._unreadIndicator = layout.FindElement(UnreadIndicatorId);
+        if (c._unreadIndicator is not null)
+        {
+            c._unreadIndicator.Visible = false;
+            if (c._unreadIndicator is UiButton unread)
+                unread.OnClick = c.ScrollToNewestAndClearUnread;
+        }
+
         // ── Input ────────────────────────────────────────────────────────
         // Editable/selectable/one-line semantics and state sprites came from the
         // imported property/state bags. The controller supplies runtime services only.
@@ -781,6 +805,16 @@ public sealed class ChatWindowController : IRetainedWindowStateController, IReta
             return _cachedTranscriptLines;
         }
 
+        // Sampled BEFORE the rebuild, exactly as retail samples IsAtVerticalEnd
+        // before the new line lands: if the player had scrolled up, the
+        // arriving text is unseen and the view must NOT be yanked down.
+        if (_cachedTranscriptRevision != revision
+            && _cachedTranscriptRevision >= 0
+            && !Transcript.Scroll.AtEnd)
+        {
+            _hasUnseenText = true;
+        }
+
         var detailed = vm.RecentLinesDetailed();
         if (detailed.Count == 0)
         {
@@ -856,6 +890,29 @@ public sealed class ChatWindowController : IRetainedWindowStateController, IReta
         return false;
     }
 
+    /// <summary>
+    /// Jumps to the newest text and clears the unread flag — retail's own
+    /// handler for a click on the indicator.
+    /// </summary>
+    internal void ScrollToNewestAndClearUnread()
+    {
+        Transcript.Scroll.ScrollToEnd();
+        _hasUnseenText = false;
+    }
+
+    /// <summary>
+    /// Keeps the indicator in step with the view. Reaching the bottom by ANY
+    /// means clears it — the wheel, the scrollbar, or the click above — so it
+    /// cannot be left lit over text the player has already read.
+    /// </summary>
+    internal void UpdateUnreadIndicator()
+    {
+        if (Transcript.Scroll.AtEnd)
+            _hasUnseenText = false;
+        if (_unreadIndicator is not null)
+            _unreadIndicator.Visible = _hasUnseenText;
+    }
+
     /// <summary>Aims the chat entry at <paramref name="name"/> and focuses it.</summary>
     internal void StartTell(string name)
     {
diff --git a/src/AcDream.App/UI/RetailUiRuntime.cs b/src/AcDream.App/UI/RetailUiRuntime.cs
index faad50d6..e666c753 100644
--- a/src/AcDream.App/UI/RetailUiRuntime.cs
+++ b/src/AcDream.App/UI/RetailUiRuntime.cs
@@ -861,6 +861,10 @@ public sealed class RetailUiRuntime : IDisposable
         NegativeEffectsController?.Tick();
         LinkStatusUiController?.Tick();
         IndicatorBarController?.Tick();
+        // Campaign CT slice C1: keeps the "unseen text" indicator in step with
+        // the transcript's scroll position, so reaching the bottom by ANY
+        // means clears it.
+        _chatWindowController?.UpdateUnreadIndicator();
         JumpPowerbarController?.Tick();
         SecureTradeController?.Tick();
         SelectedObjectController?.Tick(deltaSeconds);
diff --git a/tests/AcDream.App.Tests/UI/Layout/ChatWindowControllerTests.cs b/tests/AcDream.App.Tests/UI/Layout/ChatWindowControllerTests.cs
index 46f7d5c4..7cf98d0d 100644
--- a/tests/AcDream.App.Tests/UI/Layout/ChatWindowControllerTests.cs
+++ b/tests/AcDream.App.Tests/UI/Layout/ChatWindowControllerTests.cs
@@ -158,6 +158,48 @@ public class ChatWindowControllerTests
         Assert.NotNull(ctrl);
     }
 
+    // ── CT-C1: the unseen-text indicator ────────────────────────────────
+
+    private static ChatWindowController BindController()
+    {
+        var (rootInfo, layout, vm) = BuildTestTree();
+        var bus = new CaptureBus();
+        ChatWindowController? ctrl = ChatWindowController.Bind(
+            rootInfo, layout, vm, () => bus, new ChatWindowState(), null, null, NoTex);
+        Assert.NotNull(ctrl);
+        return ctrl!;
+    }
+
+    [Fact]
+    public void ReachingTheBottomClearsTheUnseenFlagHoweverYouGotThere()
+    {
+        // Retail clears on arrival at the bottom, not only on clicking the
+        // indicator — otherwise scrolling down with the wheel would leave it
+        // lit over text the player has just read.
+        ChatWindowController ctrl = BindController();
+        ctrl.Transcript.Scroll.SetExtents(contentHeight: 500, viewHeight: 100);
+        ctrl.Transcript.Scroll.SetScrollY(0);        // scrolled up
+        Assert.False(ctrl.Transcript.Scroll.AtEnd);
+
+        ctrl.Transcript.Scroll.ScrollToEnd();
+        ctrl.UpdateUnreadIndicator();
+
+        Assert.True(ctrl.Transcript.Scroll.AtEnd);
+    }
+
+    [Fact]
+    public void ClickingTheIndicatorJumpsToTheNewestText()
+    {
+        ChatWindowController ctrl = BindController();
+        ctrl.Transcript.Scroll.SetExtents(contentHeight: 500, viewHeight: 100);
+        ctrl.Transcript.Scroll.SetScrollY(0);
+        Assert.False(ctrl.Transcript.Scroll.AtEnd);
+
+        ctrl.ScrollToNewestAndClearUnread();
+
+        Assert.True(ctrl.Transcript.Scroll.AtEnd);
+    }
+
     [Fact]
     public void StartTell_PrefillsTheEntryAndPutsTheCaretAtTheEnd()
     {