diff --git a/components/reasoning-workspace.jsx b/components/reasoning-workspace.jsx
index a9e1291..fbd2d41 100644
--- a/components/reasoning-workspace.jsx
+++ b/components/reasoning-workspace.jsx
@@ -143,6 +143,12 @@ function FocusedQuestionBody({
   onUpdateFindingDisposition,
   onUpdateFindingProposition,
 }) {
+  // ── Active-thread contribution scoping (v0.52) ──
+  // focusedContributions is scenario-wide; present only the active node's contributions.
+  const threadContribs = (focusedContributions || []).filter(
+    (c) => c.targetNodeId === nodeId || c.originatingTargetNodeId === nodeId,
+  );
+
   const hasContent = focused?.question?.trim() || formulationStep === "active" || processingStep === "active" || focused?.error;
   const hasResult = Boolean(focused?.result);
   const hasAnswer = Boolean(focused?.answer);
@@ -151,7 +157,7 @@ function FocusedQuestionBody({
   // Completed context: result (primary) OR prior contributions (fallback during processing/error).
   // Processing and error are transient states — they must NOT collapse completed context.
   const hasCompletedContext = Boolean(focused?.result) || (() => {
-    const pc = [...(focusedContributions || [])].reverse().find((c) => c?.question && c?.answer);
+    const pc = [...threadContribs].reverse().find((c) => c?.question && c?.answer);
     return !!pc;
   })();
 
@@ -159,7 +165,7 @@ function FocusedQuestionBody({
   // After setFollowUpQuestion() mutates focused.question/answer, derive from the
   // latest completed Contribution so the narrative remains correct.
   // Active follow-up detection: primary via result (when result exists), fallback via priorContribs (error state may have null result).
-  const priorContribs = [...(focusedContributions || [])].reverse();
+  const priorContribs = [...threadContribs].reverse();
   // Follow-ups from result are primary; priorContribs is fallback when result is null.
   const followUpsFromResult = focused?.result?.possibleFollowUpQuestions || [];
   const hasActiveFollowUpFromResult =
diff --git a/docs/current-handoff.md b/docs/current-handoff.md
index a6d6aae..b739f5f 100644
--- a/docs/current-handoff.md
+++ b/docs/current-handoff.md
@@ -276,8 +276,46 @@ A real completed investigation reached zero Open Questions, clarified questions
 - This session corrected placement via Edit only; deterministic verification via targeted Vitest (145 tests) and build — deliberately did not repeat Playwright
 - All 145 tests pass; production build compiles successfully
 
-**Open defects (unchanged):**
-- Focused-investigation state bleed: newly selected Open Question can show stale previous-question material — separate future increment
+### Focused investigation presentation ownership — v0.52 correction (verified)
+
+**Live evidence that motivated this correction:**
+
+A fresh unanswered Question B displayed stale focused-investigation content from a previously answered Question A across every presentation surface:
+- Previously answered / Your response
+- What this tells us
+- Still unclear
+- Questions this raises
+- Assumptions
+- Connections
+
+**Root cause:** `FocusedQuestionBody` in `components/reasoning-workspace.jsx` iterated over the scenario-wide `focusedContributions` array for all derivations (`hasCompletedContext`, latest completed contribution, and every effective-presentation fallback: observations, uncertainties, follow-ups, assumptions, relationships). No active-question scoping was applied.
+
+**Correction applied — scoped contribution presentation:**
+
+- `FocusedQuestionBody` now derives a thread-local subset before any derivation:
+  ```js
+  const threadContribs = (focusedContributions || []).filter(
+    (c) => c.targetNodeId === nodeId || c.originatingTargetNodeId === nodeId,
+  );
+  ```
+- `hasCompletedContext`, latest completed contribution, and all effective presentation fallbacks use that scoped collection;
+- scenario-wide `focusedContributions` history is preserved in memory — only the presentation derivation is narrowed;
+- `originatingTargetNodeId` is also checked so follow-up contributions remain attributed to their originating question;
+- fresh Question B no longer inherits Question A's focused presentation content;
+- reopening or revisiting Question A still correctly uses Question A's own historical contribution content.
+
+**Verified:**
+- targeted Vitest (`tests/open-questions-vs-assumptions.test.jsx`) — 3 new test cases (fresh B scoped to zero, active A retains its history, originatingTargetNodeId scoping) — pass
+- `npm run build` — compiles successfully
+- Rob manually verified the live UI on a persisted investigation: fresh unanswered Question B no longer shows stale focused-investigation content from Question B; confirmed across all six presentation surfaces listed above
+
+**Verification notes:**
+- Claude Playwright was not used for final verification because the canonical dev server was unavailable at that point
+- Full Vitest suite was not re-run in this session (only targeted regression test)
+
+### Open defects
+
+- **Focused-investigation state bleed**: Resolved by v0.52 correction above (scoped presentation derivation). Verified by targeted Vitest, build, and Rob manual visual verification.
 - Empty Done `no_episodic_content`: choosing Done without episodic content can produce `{ success: false, stage: "preparation", error: "no_episodic_content" }` — separate future increment
 
-**Next restart point:** Place milestone at Open Questions position when reverting placement correction. See v0.51 placement section above for the exact ternary pattern.
+**Next restart point:** The empty-Done `no_episodic_content` 400. Implement and verify that a Done action taken when no episodic evidence exists produces the same user-facing state (CU refresh with appropriate messaging) without a 400 error.
diff --git a/tests/open-questions-vs-assumptions.test.jsx b/tests/open-questions-vs-assumptions.test.jsx
index 8de66c3..60b9dea 100644
--- a/tests/open-questions-vs-assumptions.test.jsx
+++ b/tests/open-questions-vs-assumptions.test.jsx
@@ -2875,4 +2875,136 @@ describe("Zero Open Questions — end-of-investigation review invitation", () =>
     expect(state.showInvitation).toBe(false);
     expect(state.clarificationNodes).toHaveLength(0);
   });
+});
+
+// ── v0.52: Focused presentation ownership — fresh question must not inherit another's content ──
+
+describe("v0.52 focused presentation is scoped to active question ownership", () => {
+  // Simulates the exact scoped-contributions derivation in FocusedQuestionBody (v0.52 fix)
+  function deriveScopedContribs(focusedContributions, nodeId) {
+    return (focusedContributions || []).filter(
+      (c) => c.targetNodeId === nodeId || c.originatingTargetNodeId === nodeId,
+    );
+  }
+
+  function simulateFQB(priorContribs, focused) {
+    const hasAnswer = Boolean(focused?.answer);
+    const hasResult = Boolean(focused?.result);
+    const hasCompletedContext = hasResult || (() => {
+      const pc = [...priorContribs].reverse().find((c) => c?.question && c?.answer);
+      return !!pc;
+    })();
+
+    const latestCompletedContrib = priorContribs.find((c) => c?.question && c?.answer);
+    const effectiveObservations = focused?.result?.observations ?? priorContribs.find((c) => c?.observations)?.observations;
+    const effectiveUncertainties = focused?.result?.uncertainties ?? priorContribs.find((c) => c?.uncertainties)?.uncertainties;
+    const effectiveFollowUps = focused?.result?.possibleFollowUpQuestions || priorContribs.find((c) => c?.possibleFollowUpQuestions)?.possibleFollowUpQuestions;
+    const effectiveAssumptions = focused?.result?.assumptions || priorContribs.find((c) => c?.assumptions)?.assumptions;
+    const effectiveRelationships = focused?.result?.relationships || priorContribs.find((c) => c?.relationships)?.relationships;
+
+    return {
+      hasCompletedContext,
+      latestCompletedContrib,
+      effectiveObservations,
+      effectiveUncertainties,
+      effectiveFollowUps,
+      effectiveAssumptions,
+      effectiveRelationships,
+    };
+  }
+
+  // ── Scenario: Question A has historical contributions; Question B is fresh ──
+  const questionAContrib = {
+    id: "contrib-a-1",
+    targetNodeId: "node-A",
+    originatingTargetNodeId: "node-A",
+    question: "What drives user engagement?",
+    answer: "Social proof and urgency signals.",
+    observations: ["Users respond to countdown timers"],
+    uncertainties: ["Unclear if this generalises beyond SaaS"],
+    possibleFollowUpQuestions: ["What is the optimal timer duration?"],
+    assumptions: ["Users are time-pressured"],
+    relationships: [["engagement", "temporal_pressure"]],
+  };
+
+  const scenarioWideContributions = [questionAContrib];
+
+  it("Case 1 — fresh B has no active-thread contributions (Question A content absent from Question B presentation)", () => {
+    const activeNodeId = "node-B"; // fresh question, no own contributions
+
+    const scopedContribs = deriveScopedContribs(scenarioWideContributions, activeNodeId);
+    expect(scopedContribs).toHaveLength(0);
+
+    const focused = {
+      status: "formulated",
+      question: "How many users visit daily?",
+      answer: null,
+      result: null,
+    };
+
+    const derived = simulateFQB(scopedContribs, focused);
+
+    // None of the A-owned fields should appear
+    expect(derived.hasCompletedContext).toBe(false);
+    expect(derived.latestCompletedContrib).toBeUndefined();
+    expect(derived.effectiveObservations).toBeUndefined();
+    expect(derived.effectiveUncertainties).toBeUndefined();
+    expect(derived.effectiveFollowUps).toBeUndefined();
+    expect(derived.effectiveAssumptions).toBeUndefined();
+    expect(derived.effectiveRelationships).toBeUndefined();
+  });
+
+  it("Case 2 — active node = A retains its own contribution history", () => {
+    const activeNodeId = "node-A"; // reopen Question A
+
+    const scopedContribs = deriveScopedContribs(scenarioWideContributions, activeNodeId);
+    expect(scopedContribs).toHaveLength(1);
+    expect(scopedContribs[0].id).toBe("contrib-a-1");
+
+    const focused = {
+      status: "formulated",
+      question: questionAContrib.question,
+      answer: questionAContrib.answer,
+      result: {
+        observations: questionAContrib.observations,
+        uncertainties: questionAContrib.uncertainties,
+        possibleFollowUpQuestions: questionAContrib.possibleFollowUpQuestions,
+        assumptions: questionAContrib.assumptions,
+        relationships: questionAContrib.relationships,
+      },
+    };
+
+    const derived = simulateFQB(scopedContribs, focused);
+
+    // A's own content is present
+    expect(derived.hasCompletedContext).toBe(true);
+    expect(derived.latestCompletedContrib.id).toBe("contrib-a-1");
+    expect(derived.effectiveObservations).toEqual(questionAContrib.observations);
+    expect(derived.effectiveUncertainties).toEqual(questionAContrib.uncertainties);
+    expect(derived.effectiveFollowUps).toEqual(questionAContrib.possibleFollowUpQuestions);
+    expect(derived.effectiveAssumptions).toEqual(questionAContrib.assumptions);
+    expect(derived.effectiveRelationships).toEqual(questionAContrib.relationships);
+  });
+
+  it("Case 3 — originatingTargetNodeId also scopes (follow-up contribution belongs to A)", () => {
+    const followUpContrib = {
+      id: "contrib-a-followup",
+      targetNodeId: "node-A-followup-intermediate",
+      originatingTargetNodeId: "node-A",
+      question: "What is the optimal timer duration?",
+      answer: "15-30 seconds is the sweet spot.",
+      observations: ["Timer above the CTA works best"],
+    };
+
+    const contribs = [followUpContrib];
+
+    // Matches A via originatingTargetNodeId
+    const scopedA = deriveScopedContribs(contribs, "node-A");
+    expect(scopedA).toHaveLength(1);
+    expect(scopedA[0].id).toBe("contrib-a-followup");
+
+    // Does NOT match B
+    const scopedB = deriveScopedContribs(contribs, "node-B");
+    expect(scopedB).toHaveLength(0);
+  });
 });
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