diff --git a/internal/plugin/dnd_expedition_extract.go b/internal/plugin/dnd_expedition_extract.go
index 899059e..6cd971d 100644
--- a/internal/plugin/dnd_expedition_extract.go
+++ b/internal/plugin/dnd_expedition_extract.go
@@ -110,6 +110,66 @@ func forceExtractExpeditionForRunLoss(userID id.UserID, reason string) {
 	}
 }
 
+// finalizeExpeditionOnZoneClear bridges the run-complete seam (boss down,
+// no outgoing edges) into expedition completion — the success-path twin of
+// forceExtractExpeditionForRunLoss. When the cleared run is the active
+// expedition's current run AND the clear finishes the whole zone (a
+// single-region zone, or the zone-boss region of a multi-region zone), it
+// flips the expedition to 'complete', records boss_defeated, and awards
+// completion milestones. Returns the rendered milestone lines for the caller
+// to append to the run-complete message.
+//
+// No-op (nil) for standalone runs and for mid-zone region clears, which
+// leave the expedition active so inter-region travel can continue. Without
+// this, a cleared zone leaves the expedition 'active' forever and the
+// ambient ticker keeps DMing about a dungeon the player already finished.
+func (p *AdventurePlugin) finalizeExpeditionOnZoneClear(userID id.UserID, runID string) []string {
+	exp, err := getActiveExpedition(userID)
+	if err != nil || exp == nil {
+		return nil
+	}
+	if exp.RunID != runID {
+		return nil // the completed run isn't this expedition's current run
+	}
+
+	if IsMultiRegionZone(exp.ZoneID) {
+		region, ok := CurrentRegion(exp)
+		if !ok {
+			return nil
+		}
+		if _, err := MarkRegionBossDefeated(exp, region.ID); err != nil {
+			slog.Warn("expedition: mark region boss defeated",
+				"user", userID, "expedition", exp.ID, "region", region.ID, "err", err)
+		}
+		if !region.IsZoneBoss {
+			return nil // region cleared; expedition continues to the next region
+		}
+	} else {
+		// Single-region zone: there's no region registry to flip through
+		// MarkRegionBossDefeated, so set the zone-level flag directly.
+		exp.BossDefeated = true
+		if _, err := db.Get().Exec(`
+			UPDATE dnd_expedition
+			   SET boss_defeated = 1,
+			       last_activity = CURRENT_TIMESTAMP
+			 WHERE expedition_id = ?`, exp.ID); err != nil {
+			slog.Warn("expedition: set boss defeated on zone clear",
+				"user", userID, "expedition", exp.ID, "err", err)
+		}
+	}
+
+	// completeExpedition must run before AwardCompletionMilestones — the
+	// latter gates on status == 'complete'.
+	if err := completeExpedition(exp.ID, ExpeditionStatusComplete); err != nil {
+		slog.Warn("expedition: complete on zone clear",
+			"user", userID, "expedition", exp.ID, "err", err)
+		return nil
+	}
+	exp.Status = ExpeditionStatusComplete
+	_ = retireAllRegionRuns(exp)
+	return p.AwardCompletionMilestones(exp, false)
+}
+
 // getResumableExpedition returns the most recent 'extracting' row for the
 // user, regardless of age (caller checks the 7-day window).
 func getResumableExpedition(userID id.UserID) (*Expedition, error) {
diff --git a/internal/plugin/dnd_expedition_zone_clear_test.go b/internal/plugin/dnd_expedition_zone_clear_test.go
new file mode 100644
index 0000000..0a052ef
--- /dev/null
+++ b/internal/plugin/dnd_expedition_zone_clear_test.go
@@ -0,0 +1,116 @@
+package plugin
+
+import (
+	"testing"
+
+	"maunium.net/go/mautrix/id"
+)
+
+// Single-region zone: clearing the run completes the wrapping expedition
+// and flips BossDefeated.
+func TestFinalizeExpeditionOnZoneClear_SingleRegionCompletes(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@zclear-single:example.org")
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneSunkenTemple, "run-1",
+		ExpeditionSupplies{Max: 10, Current: 10, DailyBurn: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if exp.RunID != "run-1" {
+		t.Fatalf("setup: RunID = %q", exp.RunID)
+	}
+
+	p := &AdventurePlugin{}
+	p.finalizeExpeditionOnZoneClear(uid, "run-1")
+
+	if act, _ := getActiveExpedition(uid); act != nil {
+		t.Fatalf("expedition still active after zone clear: status=%s", act.Status)
+	}
+	loaded, _ := getExpedition(exp.ID)
+	if loaded.Status != ExpeditionStatusComplete {
+		t.Errorf("status = %q, want %q", loaded.Status, ExpeditionStatusComplete)
+	}
+	if !loaded.BossDefeated {
+		t.Error("BossDefeated not set after single-region zone clear")
+	}
+}
+
+// A run that isn't the expedition's current run must not complete it.
+func TestFinalizeExpeditionOnZoneClear_RunMismatchNoop(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@zclear-mismatch:example.org")
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneSunkenTemple, "run-1",
+		ExpeditionSupplies{Max: 10, Current: 10, DailyBurn: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	p := &AdventurePlugin{}
+	p.finalizeExpeditionOnZoneClear(uid, "some-other-run")
+
+	loaded, _ := getExpedition(exp.ID)
+	if loaded.Status != ExpeditionStatusActive {
+		t.Errorf("status = %q, want active (mismatched run should be no-op)", loaded.Status)
+	}
+}
+
+// Multi-region zone: clearing a non-boss region marks it cleared but leaves
+// the expedition active so inter-region travel can continue.
+func TestFinalizeExpeditionOnZoneClear_MidZoneRegionStaysActive(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@zclear-midzone:example.org")
+	defer cleanupExpeditions(uid)
+
+	// CurrentRegion defaults to the first region (underdark_surface_tunnels,
+	// not the zone boss).
+	exp, err := startExpedition(uid, ZoneUnderdark, "run-1",
+		ExpeditionSupplies{Max: 10, Current: 10, DailyBurn: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	p := &AdventurePlugin{}
+	p.finalizeExpeditionOnZoneClear(uid, "run-1")
+
+	loaded, _ := getExpedition(exp.ID)
+	if loaded.Status != ExpeditionStatusActive {
+		t.Errorf("status = %q, want active after non-boss region clear", loaded.Status)
+	}
+	if !IsRegionCleared(loaded, "underdark_surface_tunnels") {
+		t.Error("first region not marked cleared")
+	}
+	if loaded.BossDefeated {
+		t.Error("BossDefeated set on a non-boss region clear")
+	}
+}
+
+// Multi-region zone: clearing the zone-boss region completes the expedition.
+func TestFinalizeExpeditionOnZoneClear_ZoneBossRegionCompletes(t *testing.T) {
+	setupZoneRunTestDB(t)
+	uid := id.UserID("@zclear-zoneboss:example.org")
+	defer cleanupExpeditions(uid)
+
+	exp, err := startExpedition(uid, ZoneUnderdark, "run-1",
+		ExpeditionSupplies{Max: 10, Current: 10, DailyBurn: 1})
+	if err != nil {
+		t.Fatal(err)
+	}
+	if err := setCurrentRegion(exp, "underdark_deep_throne"); err != nil {
+		t.Fatal(err)
+	}
+
+	p := &AdventurePlugin{}
+	p.finalizeExpeditionOnZoneClear(uid, "run-1")
+
+	loaded, _ := getExpedition(exp.ID)
+	if loaded.Status != ExpeditionStatusComplete {
+		t.Errorf("status = %q, want complete after zone-boss region clear", loaded.Status)
+	}
+	if !loaded.BossDefeated {
+		t.Error("BossDefeated not set after zone-boss region clear")
+	}
+}
diff --git a/internal/plugin/dnd_zone_cmd.go b/internal/plugin/dnd_zone_cmd.go
index f5514f7..41fa98f 100644
--- a/internal/plugin/dnd_zone_cmd.go
+++ b/internal/plugin/dnd_zone_cmd.go
@@ -604,6 +604,16 @@ func (p *AdventurePlugin) advanceOnceWithOpts(ctx MessageContext, compact bool)
 				b.WriteString("• " + id + "\n")
 			}
 		}
+		// Success-path expedition close-out: flip the wrapping expedition to
+		// 'complete' (when this clear finishes the whole zone) and surface any
+		// completion milestones. No-op for standalone runs / mid-zone region
+		// clears.
+		if lines := p.finalizeExpeditionOnZoneClear(ctx.Sender, run.RunID); len(lines) > 0 {
+			b.WriteString("\n")
+			for _, line := range lines {
+				b.WriteString(line)
+			}
+		}
 		return advanceResult{
 			preStream: preStream,
 			intro:     intro,