diff --git a/apps/web/src/components/chat/MessagesTimeline.logic.test.ts b/apps/web/src/components/chat/MessagesTimeline.logic.test.ts
index b0436875c2a330cdfe37bd93607e0973779f6293..94727086f1868769e1cfa7c6530c91f512db2937 100644
--- a/apps/web/src/components/chat/MessagesTimeline.logic.test.ts
+++ b/apps/web/src/components/chat/MessagesTimeline.logic.test.ts
@@ -1170,11 +1170,10 @@ describe("deriveMessagesTimelineRows", () => {
       })),
     ];
 
-    const rows = deriveMessagesTimelineRows({
-      timelineEntries,
+    const input = {
       latestTurn: {
         turnId,
-        state: "error",
+        state: "error" as const,
         startedAt: "2026-01-01T00:00:00Z",
         completedAt: "2026-01-01T00:00:10Z",
       },
@@ -1182,7 +1181,8 @@ describe("deriveMessagesTimelineRows", () => {
       activeTurnStartedAt: null,
       turnDiffSummaryByAssistantMessageId: new Map(),
       revertTurnCountByUserMessageId: new Map(),
-    });
+    };
+    const rows = deriveMessagesTimelineRows({ ...input, timelineEntries });
 
     expect(rows.map((row) => row.id)).toEqual([
       "turn-fold:turn-1",
@@ -1205,6 +1205,11 @@ describe("deriveMessagesTimelineRows", () => {
       showAssistantMeta: false,
       showAssistantCopyButton: false,
     });
+    expect(
+      deriveMessagesTimelineRows({ ...input, timelineEntries: timelineEntries.slice(0, 3) }).map(
+        (row) => row.id,
+      ),
+    ).toEqual(["turn-fold:turn-1", "assistant-final-entry"]);
   });
 
   it("folds all assistant messages before the terminal message", () => {
diff --git a/apps/web/src/components/chat/MessagesTimeline.logic.ts b/apps/web/src/components/chat/MessagesTimeline.logic.ts
index 7b01caf16d0976d007b71f4eea52c580abf82d17..36c90c89563cce79c4ecc52e45f334f82b749c68 100644
--- a/apps/web/src/components/chat/MessagesTimeline.logic.ts
+++ b/apps/web/src/components/chat/MessagesTimeline.logic.ts
@@ -542,8 +542,8 @@ function workEntryIsActiveTurnActivity(entry: WorkLogEntry): boolean {
 
 /**
  * Settled turns fold activity before their terminal assistant message behind
- * a "Worked for ..." row. Work that lands after that message stays visible so
- * failed or interrupted turns do not hide their trailing tool-call summary.
+ * a "Worked for ..." row. A single ordinary activity after that message joins
+ * the fold, while larger groups and failures stay visible as a trailing summary.
  */
 function deriveTurnFolds(input: {
   timelineEntries: ReadonlyArray<TimelineEntry>;
@@ -623,7 +623,11 @@ function deriveTurnFolds(input: {
       }
       const isCompaction =
         entry.kind === "work" && entry.entry.sourceActivityKind === "context-compaction";
-      if (!isCompaction && index > terminalEntryIndex) {
+      const isSingleTrailingActivity =
+        group.entries.length === terminalEntryIndex + 2 &&
+        entry.kind === "work" &&
+        !workEntryDisplayIndicatesToolFailure(entry.entry);
+      if (!isCompaction && index > terminalEntryIndex && !isSingleTrailingActivity) {
         continue;
       }
       // Agent-spawn CTA rows never fold: workflows outlive their launching
diff --git a/apps/web/src/components/chat/MessagesTimeline.test.tsx b/apps/web/src/components/chat/MessagesTimeline.test.tsx
index 7cb64023d0e4c9ebf716ff87e448bf524a18f67c..ccf9be69a47177beda3d623c65abe9e33fcb4bc3 100644
--- a/apps/web/src/components/chat/MessagesTimeline.test.tsx
+++ b/apps/web/src/components/chat/MessagesTimeline.test.tsx
@@ -1135,7 +1135,7 @@ describe("MessagesTimeline", () => {
               label: "Ran command",
               tone: "tool",
               itemType: "command_execution",
-              toolLifecycleStatus: "completed",
+              toolLifecycleStatus: "failed",
             },
           },
         ]}