diff --git a/components/investigation-map.jsx b/components/investigation-map.jsx
index 1360013..1bf3d1d 100644
--- a/components/investigation-map.jsx
+++ b/components/investigation-map.jsx
@@ -82,12 +82,12 @@ export default function InvestigationMap({ turnCount = 0 }) {
   if (!hasActiveTopics && groups.established.length === 0) return null;
 
   return (
-    <div className="rounded-lg border border-gray-200 bg-white p-5" role="region" aria-label="Investigation map">
+    <div className="rounded-lg border border-gray-200 bg-white p-5" role="region" aria-label="Investigation map preview">
       <h2 className="mb-1 text-sm font-semibold uppercase tracking-wide text-gray-500">
-        Investigation Map
+        Investigation Map Preview
       </h2>
       <p className="mb-3 text-xs text-gray-400">
-        We are building an understanding of your situation one question at a time.
+        This preview shows where a future reasoning map may appear. Its final shape will emerge from the reasoning engine.
       </p>
 
       <div className="space-y-px border-t border-gray-100 pt-3" role="list" aria-label="Investigation topics">
diff --git a/docs/reasoning-contract-backlog.md b/docs/reasoning-contract-backlog.md
index dad316c..a165481 100644
--- a/docs/reasoning-contract-backlog.md
+++ b/docs/reasoning-contract-backlog.md
@@ -99,10 +99,32 @@ temporary workaround and the desired eventual contract.
 
 ## Investigation Map (Workspace UX)
 
+### Open design decision — final map shape intentionally unresolved
+
+The current Investigation Map implementation exists **only** to validate:
+- placement within the workspace;
+- information density at preview scale;
+- status presentation (established / current / unknown);
+- responsive layout across viewports;
+- interaction with surrounding components across turns.
+
+It is NOT a committed design. The eventual map should be derived from the reasoning engine, not from hard-coded UI categories.
+
+The following are unresolved design questions — do NOT treat them as agreed contract fields:
+
+- Will the engine provide a flat topic list, hierarchy, branches, or grouped clusters?
+- Who determines ordering — engine or user interaction?
+- Will there be evidence counts, completion percentages, or path metadata?
+- How does the map handle dynamic addition/removal of topics during investigation?
+
+### Current entry (temporary)
+
 | Feature                | UI need                            | Temporary mock                                      | Desired reasoning output                                       | Likely stage           | Notes                                                    |
 | ---------------------- | ---------------------------------- | --------------------------------------------------- | -------------------------------------------------------------- | ---------------------- | -------------------------------------------------------- |
-| InvestigationMap       | Visible investigation progress     | Mock topic set with manual turn-based status progression | Engine emits `investigationTopics: [{ title, status, ordering?, evidenceCount? }]` | Each turn — start and update response | UI displays topics in engine-determined order; statuses: "established" / "current" / "unknown" |
-| InvestigationMap       | Topic status evolution across turns | Hardcoded PROGRESSION array indexed by `investigationHistory.length` | Engine determines which topics are established, active, or unknown at each turn | Question selection phase | Topics should not expose graph internals; plain-language labels only |
+| InvestigationMap       | Visible investigation progress     | **mock-only placeholder**: minimal set of neutral topic names (≤5) with manual turn-based status progression | Engine emits `investigationTopics: [{ title, status, ordering?, evidenceCount? }]` | Each turn — start and update response | UI displays topics in engine-determined order; statuses: "established" / "current" / "unknown" |
+| InvestigationMap       | Topic status evolution across turns | **mock-only placeholder**: Hardcoded PROGRESSION array indexed by `investigationHistory.length` | Engine determines which topics are established, active, or unknown at each turn | Question selection phase | Topics should not expose graph internals; plain-language labels only |
+
+The current adapter (`lib/map/investigation-map-adapter.js`) uses generic placeholder names (e.g. "Starting point", "Current focus") explicitly because they do NOT represent a domain-specific design decision.
 
 ## Open Questions / Future Work
 
diff --git a/lib/map/investigation-map-adapter.js b/lib/map/investigation-map-adapter.js
index 89171fe..015e2a0 100644
--- a/lib/map/investigation-map-adapter.js
+++ b/lib/map/investigation-map-adapter.js
@@ -1,50 +1,46 @@
 /**
- * Investigation Map Mock Adapter
- *
- * Provides the Investigation Map with a set of investigation topics and their
- * current status (established / current / unknown).
- *
- * TODO: Replace this mock adapter when the reasoning engine emits real
- * investigation data. The eventual contract should provide:
- *   - `investigationTopics`: [{ title, status, evidenceCount? }]
- *   - `topicStatus` values: "established" | "current" | "unknown"
- *   - `topicOrdering`: the reasoning-engine-determined sequence
- *   - `evidenceCount`: optional count of supporting evidence per topic
- *
- * Until then, this adapter drives a realistic mock progression across turns.
+ * ┌─────────────────────────────────────────────────────────────────────┐
+ * │  INVESTIGATION MAP — UX PLACEHOLDER ADAPTER                          │
+ * │                                                                      │
+ * │  This adapter drives a minimal mock to validate UX placement,        │
+ * │  spacing, status appearance, responsive behaviour, and state         │
+ * │  change across turns.                                                │
+ * │                                                                      │
+ * │  The topic names below are mock-only placeholders. They are NOT       │
+ * │  part of the reasoning contract and do NOT imply the final map       │
+ * │  structure — which may be hierarchical, grouped, branching, or       │
+ * │  something else entirely.                                            │
+ * │                                                                      │
+ * │  The UI will eventually consume real reasoning output once that      │
+ * │  design stabilises.                                                  │
+ * └─────────────────────────────────────────────────────────────────────┘
  */
 
-/** @type {Array<{ title: string }>} */
+/** @type {Array<{ title: string }>} — mock-only placeholder names */
 const TOPICS = [
-  { title: "Central situation" },
-  { title: "Complaint trend direction" },
-  { title: "Measurement basis" },
-  { title: "Production volume context" },
-  { title: "QA process changes" },
-  { title: "Product change log" },
-  { title: "Support response patterns" },
-  { title: "Prior similar cases" },
+  { title: "Starting point" },
+  { title: "What is known" },
+  { title: "Current focus" },
+  { title: "Questions still open" },
+  { title: "Possible explanations" },
 ];
 
 /**
  * Status progression per turn index.
  * The reasoning engine will eventually determine these values.
+ *
+ * With N placeholder topics we have N-1 progressive states (indices 0 to N-2).
+ * Beyond that the map stabilises: all topics established except the last one current.
  */
 const PROGRESSION = [
   // Turn 0 — initial analysis just started
-  ["established", "unknown", "unknown", "unknown", "unknown", "unknown", "unknown", "unknown"],
+  ["established", "current", "unknown", "unknown", "unknown"],
   // Turn 1 — first question answered
-  ["established", "established", "current", "unknown", "unknown", "unknown", "unknown", "unknown"],
+  ["established", "established", "current", "unknown", "unknown"],
   // Turn 2 — second question answered
-  ["established", "established", "established", "current", "unknown", "unknown", "unknown", "unknown"],
-  // Turn 3 — third question answered
-  ["established", "established", "established", "established", "current", "unknown", "unknown", "unknown"],
-  // Turn 4 — fourth question answered
-  ["established", "established", "established", "established", "established", "current", "unknown", "unknown"],
-  // Turn 5 — fifth question answered
-  ["established", "established", "established", "established", "established", "established", "current", "unknown"],
-  // Turn 6+ — final turn
-  ["established", "established", "established", "established", "established", "established", "established", "current"],
+  ["established", "established", "established", "current", "unknown"],
+  // Turn 3+ — third answer and beyond (all topics resolved, last in progress)
+  ["established", "established", "established", "established", "current"],
 ];
 
 /**
@@ -53,7 +49,8 @@ const PROGRESSION = [
  * @returns {{ title: string, status: 'established' | 'current' | 'unknown' }[]}
  */
 export function getInvestigationMapTopics(turnIndex) {
-  const idx = Math.min(turnIndex, PROGRESSION.length - 1);
+  // Clamp to last progression entry so the map stabilises when all topics are covered
+  const idx = Math.min(Math.max(turnIndex, 0), PROGRESSION.length - 1);
   return TOPICS.map((topic, i) => ({
     title: topic.title,
     status: PROGRESSION[idx][i],
diff --git a/tests/e2e/happy-path.spec.js b/tests/e2e/happy-path.spec.js
index fb0cbd7..d591e33 100644
--- a/tests/e2e/happy-path.spec.js
+++ b/tests/e2e/happy-path.spec.js
@@ -371,7 +371,7 @@ test("update submission replaces response panel with loading card, preserves con
 
 /* ═══════ Test: investigation map appears and evolves across turns ═ */
 
-test("investigation map: appears after start, topics evolve across mocked turns", async ({ page }) => {
+test("investigation map preview: appears after start, topics evolve across mocked turns", async ({ page }) => {
   await page.goto("/");
 
   await page.evaluate(() => {
@@ -387,24 +387,22 @@ test("investigation map: appears after start, topics evolve across mocked turns"
   await waitForLoading(page);
   await waitForWorkspaceReady(page);
 
-  // Verify the investigation map card is present after start
-  const mapCard = page.locator('[aria-label="Investigation map"]');
+  // Verify the investigation map preview card is present after start
+  const mapCard = page.locator('[aria-label="Investigation map preview"]');
   await expect(mapCard).toBeVisible();
 
-  // Map heading visible
-  await expect(mapCard.getByRole("heading", { name: "Investigation Map" })).toBeVisible();
+  // Preview heading visible
+  await expect(mapCard.getByRole("heading", { name: "Investigation Map Preview" })).toBeVisible();
 
-  // Helper text visible
-  await expect(mapCard.getByText(/building an understanding/i)).toBeVisible();
+  // Placeholder note visible (secondary text)
+  await expect(mapCard.getByText(/This preview shows where a future reasoning map/i)).toBeVisible();
 
-  // At turn 0 (initial analysis): one topic established, one current, rest unknown
-  const establishedTopics = page.locator('[data-testid="map-topic-established"]');
-  const currentTopics = page.locator('[data-testid="map-topic-current"]');
-  const unknownTopics = page.locator('[data-testid="map-topic-unknown"]');
+  // Helper for counting topics by status across turns
+  const byStatus = (status) => page.locator(`[data-testid="map-topic-${status}"]`);
 
-  await expect(establishedTopics).toHaveCount(1);
-  await expect(currentTopics).toHaveCount(1);
-  await expect(unknownTopics).toHaveCount(6);
+  // At turn 0: one established + one current (≤5 neutral placeholder topics total)
+  await expect(byStatus("established")).toHaveCount(1);
+  await expect(byStatus("current")).toHaveCount(1);
 
   // Submit first answer → turn 1: one more established, next topic becomes current
   const answerTextarea = page.locator('textarea[placeholder*=Answer]');
@@ -418,10 +416,9 @@ test("investigation map: appears after start, topics evolve across mocked turns"
     // Current investigation remains visible (context preserved)
     await expect(page.getByRole("heading", { name: "Current investigation" })).toBeVisible({ timeout: 5_000 });
 
-    // Map should update: 2 established, 1 current, 5 unknown
-    await expect(establishedTopics).toHaveCount(2);
-    await expect(currentTopics).toHaveCount(1);
-    await expect(unknownTopics).toHaveCount(5);
+    // Map updated: established count increased, current still present (state shift across turns)
+    await expect(byStatus("established")).toHaveCount(2);
+    await expect(byStatus("current")).toHaveCount(1);
 
     // Submit second answer → turn 2
     const answerTextarea2 = page.locator('textarea[placeholder*=Answer]');
@@ -432,10 +429,9 @@ test("investigation map: appears after start, topics evolve across mocked turns"
       await waitForLoading(page);
       await waitForWorkspaceReady(page);
 
-      // After second update: 3 established, current shifts again
-      await expect(establishedTopics).toHaveCount(3);
-      await expect(currentTopics).toHaveCount(1);
-      await expect(unknownTopics).toHaveCount(4);
+      // After second update: established count increased again (current shifted)
+      await expect(byStatus("established")).toHaveCount(3);
+      await expect(byStatus("current")).toHaveCount(1);
     }
   }
 });
\ No newline at end of file