diff --git a/backend/api_test.go b/backend/api_test.go
index 1037808..70e5923 100644
--- a/backend/api_test.go
+++ b/backend/api_test.go
@@ -2,6 +2,7 @@ package main
 
 import (
 	"bytes"
+	"database/sql"
 	"encoding/json"
 	"fmt"
 	"net/http"
@@ -298,7 +299,7 @@ func TestFlatWireFieldSet(t *testing.T) {
 		"series_url": true, "cover": true, "last_chapter": true,
 		"last_chapter_num": true, "last_chapter_url": true, "favorite": true,
 		"latest_chapter": true, "latest_chapter_num": true, "updated_at": true,
-		"status": true, "kind": true,
+		"status": true, "kind": true, "finished": true,
 	}
 	checkFlat := func(t *testing.T, payload []byte) map[string]json.RawMessage {
 		t.Helper()
@@ -362,6 +363,52 @@ func TestFlatWireFieldSet(t *testing.T) {
 	checkFlat(t, body2)
 }
 
+// finished is derived on the wire and read-only: a client PUT echoing a cached
+// value, forward progress or not, must not change the Series' retired state,
+// so GET still reports the truth after the echo (issues #157, #160).
+func TestFinishedWireRoundTrip(t *testing.T) {
+	s, url := newTestStoreURL(t)
+	srv := newRouter(s, testConfig())
+	key := "asura:done"
+
+	putBookmark(t, srv, key, store.Bookmark{
+		Title: "Solo Leveling", SeriesURL: "https://asurascans.com/comics/done",
+		LastChapterNum: 10,
+	})
+
+	// The store writer for the flag is the admin surface's own and lands in
+	// the same wave (#158), so seed the fact with SQL, like store_test.go.
+	db, err := sql.Open("pgx", url)
+	if err != nil {
+		t.Fatalf("open db: %v", err)
+	}
+	defer db.Close()
+	if _, err := db.Exec(
+		`UPDATE series SET finished_at = 1000 WHERE site = 'asura' AND series_id = 'done'`); err != nil {
+		t.Fatalf("seed finished: %v", err)
+	}
+
+	got := getBookmarks(t, srv)
+	if len(got) != 1 || !got[0].Finished {
+		t.Fatalf("GET = %+v, want one bookmark carrying finished: true", got)
+	}
+
+	// A stale cache echoing the flag cannot un-finish (or finish) the Series.
+	for _, sent := range []bool{false, true} {
+		echoed := putBookmark(t, srv, key, store.Bookmark{
+			Title: "Solo Leveling", SeriesURL: "https://asurascans.com/comics/done",
+			LastChapterNum: 11, Finished: sent,
+		})
+		if !echoed.Finished {
+			t.Fatalf("PUT echoing Finished: %v reported finished = false, want true", sent)
+		}
+		got = getBookmarks(t, srv)
+		if !got[0].Finished {
+			t.Fatalf("GET after echoing Finished: %v = false, want the Series state preserved", sent)
+		}
+	}
+}
+
 // A PUT naming an existing series must ignore client-supplied title, cover and
 // URL — the security boundary from ADR-0003, where a hostile site's scraped
 // values could otherwise land on a shared row — while progress still lands.
diff --git a/backend/internal/store/store.go b/backend/internal/store/store.go
index e6e6c5d..f7ca35b 100644
--- a/backend/internal/store/store.go
+++ b/backend/internal/store/store.go
@@ -54,6 +54,9 @@ type Bookmark struct {
 	// Kind is the library bucket: manga or novel. Empty on the way in means
 	// "no opinion" — see Upsert.
 	Kind string `json:"kind"`
+	// Finished is the owner's retirement of the Series, derived: the flag is a
+	// Series fact and a client cannot write it — see Upsert.
+	Finished bool `json:"finished"`
 }
 
 // Series is one distinct work, shared by every bookmark that tracks it. It is
@@ -230,7 +233,8 @@ var migrations embed.FS
 // order, so the flat Bookmark reads back whole despite the split (ADR-0004).
 const bookmarkColumns = `b.site, b.series_id, s.title, s.series_url, s.cover_address,
 	b.last_chapter, b.last_chapter_num, b.last_chapter_url,
-	b.favorite, s.latest_chapter, s.latest_chapter_num, b.updated_at, b.status, s.kind`
+	b.favorite, s.latest_chapter, s.latest_chapter_num, b.updated_at, b.status, s.kind,
+	s.finished_at > 0`
 
 // seriesColumns is the series row in scanSeries order, used by the poller's
 // due query. latest_checked_at lives only on series — see MarkLatestChecked
@@ -609,6 +613,7 @@ func (s *Store) scanBookmark(scan func(...any) error) (Bookmark, error) {
 		&b.Site, &b.SeriesID, &b.Title, &b.SeriesURL, &coverAddress,
 		&b.LastChapter, &b.LastChapterNum, &b.LastChapterURL,
 		&b.Favorite, &b.LatestChapter, &latestChapterNum, &b.UpdatedAt, &b.Status, &b.Kind,
+		&b.Finished,
 	); err != nil {
 		return Bookmark{}, err
 	}
diff --git a/backend/internal/store/store_test.go b/backend/internal/store/store_test.go
index 70072f5..8480fec 100644
--- a/backend/internal/store/store_test.go
+++ b/backend/internal/store/store_test.go
@@ -934,6 +934,37 @@ func TestUpsertCreatesSeriesFromClient(t *testing.T) {
 	}
 }
 
+// The wire's finished flag is derived, never stored: the Upsert's explicit
+// column list does not name finished_at — the same omission that protects
+// cover — so a client echoing a cached flag, true or false, cannot change the
+// Series' retired state (issues #157, #160).
+func TestUpsertCannotWriteSeriesFinished(t *testing.T) {
+	store := newTestStore(t)
+	seedFinished(t, store, "asura:done", "https://asurascans.com/comics/asura:done")
+
+	for _, sent := range []bool{true, false} {
+		stored, err := store.Upsert(store.OwnerID(), Bookmark{
+			Key: "asura:done", Site: "asura", SeriesID: "done",
+			Finished: sent, UpdatedAt: 2000,
+		})
+		if err != nil {
+			t.Fatalf("Upsert(Finished: %v): %v", sent, err)
+		}
+		if !stored.Finished {
+			t.Fatalf("stored.Finished = false after echoing %v, want true", sent)
+		}
+	}
+	var finishedAt int64
+	if err := store.db.QueryRow(
+		`SELECT finished_at FROM series WHERE site = $1 AND series_id = $2`,
+		"asura", "done").Scan(&finishedAt); err != nil {
+		t.Fatalf("read finished_at: %v", err)
+	}
+	if finishedAt != 1000 {
+		t.Fatalf("series.finished_at = %v, want the seeded 1000 untouched", finishedAt)
+	}
+}
+
 // The hook is what starts creation-time acquisition, so it must fire exactly
 // once per Series — on the PUT that created it, and on no later one, whichever
 // Reader sends it.
diff --git a/backend/internal/web/static/style.css b/backend/internal/web/static/style.css
index 14a790e..1da224c 100644
--- a/backend/internal/web/static/style.css
+++ b/backend/internal/web/static/style.css
@@ -84,6 +84,7 @@
   /* One accent per action, so a press says which lane it belongs to. All three
    are held at the same weight as --brass: muted, no ember competition. */
   --slate: #7fa0c0;        /* archive */
+  --moss: #7fae86;         /* finished */
   --clay: #b5906f;         /* set chapter */
   --trash: #977671;        /* remove, resting — icons need 3:1, not 4.5:1 */
   /* A Lane needing attention: the admin page's only accent. Verdigris — cool,
@@ -147,6 +148,7 @@
     --danger-soft: #7c2c22;
     --brass: #8a681c;
     --slate: #3f6689;
+    --moss: #3d6c46;
     --clay: #7c5533;
     --trash: #8c6558;
     --patina: #1f6f66;
@@ -548,6 +550,7 @@ button { cursor: pointer; }
 .new-chapter { color: var(--ember); }
 .state { display: flex; align-items: center; gap: 4px; color: var(--mute); }
 .state svg { width: 10px; height: 10px; }
+.state.finished { color: var(--moss); }
 .is-dim .meta { color: var(--mute-2); }
 .is-dim .site-asura, .is-dim .site-demonic,
 .is-dim .site-comix, .is-dim .site-kagane,
diff --git a/backend/internal/web/templates/card.html b/backend/internal/web/templates/card.html
index d6b40e5..6175c16 100644
--- a/backend/internal/web/templates/card.html
+++ b/backend/internal/web/templates/card.html
@@ -33,6 +33,10 @@
         <span class="sep">/</span>
         <span class="state">archived</span>
         {{end}}
+        {{if .Finished}}
+        <span class="sep">/</span>
+        <span class="state finished">finished</span>
+        {{end}}
       </p>
     </div>
     <div class="actions">
diff --git a/userscript/manga-bookmark.user.js b/userscript/manga-bookmark.user.js
index d511c42..b82e753 100644
--- a/userscript/manga-bookmark.user.js
+++ b/userscript/manga-bookmark.user.js
@@ -551,6 +551,12 @@
     return b.kind || "manga";
   }
 
+  // finished is a fact about the Series, decided from the owner's side and
+  // derived on the wire (issue #157); the panel only labels it.
+  function finishedLabel(b) {
+    return b && b.finished ? "Finished" : "";
+  }
+
   // ============================================================
   // Retry queue
   //
@@ -1399,6 +1405,7 @@
       el("div", { class: "meta" }, [
         el("a", { class: "go-t t", href: cont, text: b.title || b.series_id }),
         el("div", { class: "c" + (behind ? " behind" : ""), text: sub }),
+        b.finished && el("span", { class: "finished", text: finishedLabel(b) }),
         el("div", { class: "actions" }, [
           el("button", {
             class: "btn small star" + (b.favorite ? " on" : ""),
@@ -1669,7 +1676,7 @@
       --paper: #f2ece5; --paper-hot: #f0d3cb; --paper-dim: #ddd5cb;
       --mute: #8d857c; --mute-2: #5a5450; --faint: #3a3733; --faint-2: #57504b;
       --ember: #e0452c; --ember-wash: #1a1211; --ember-ink: #150907;
-      --ember-soft: #eda798; --brass: #b8912f; --trash: #6b5450;
+      --ember-soft: #eda798; --brass: #b8912f; --trash: #6b5450; --moss: #7fae86;
       --font-display: Georgia, "Times New Roman", serif;
       --font-mono: ui-monospace, SFMono-Regular, Menlo, monospace;
       --font-body: system-ui, -apple-system, sans-serif;
@@ -1788,6 +1795,12 @@
       font: 400 17px/1.2 var(--font-display); color: var(--paper-dim);
       max-width: 100%; white-space: nowrap; overflow: hidden; text-overflow: ellipsis;
     }
+    /* finished: a Series fact, not a state class (issue #157) — same meta
+       typography as .c, moss instead of mute. */
+    .finished {
+      margin: 0; color: var(--moss);
+      font: 500 10px/1.4 var(--font-mono); letter-spacing: .12em; text-transform: uppercase;
+    }
     .item.hot .t { color: var(--paper-hot); border-bottom: 1px solid var(--ember); padding-bottom: 3px; }
     .item.dim .t { font-style: italic; color: var(--mute); }
     .c {
@@ -1838,7 +1851,7 @@
   // Exposes pure logic only — see userscript/test/logic.test.js.
   // ============================================================
   if (typeof window === "undefined" && typeof module === "object" && module.exports) {
-    module.exports = { stripBuildHash, comixSeriesId, asura, demonic, comix, kagane, anchorsFromHTML, statusOf, kindOf };
+    module.exports = { stripBuildHash, comixSeriesId, asura, demonic, comix, kagane, anchorsFromHTML, statusOf, kindOf, finishedLabel };
   }
 
   // ============================================================
diff --git a/userscript/novel-bookmark.user.js b/userscript/novel-bookmark.user.js
index cf27813..ba563d4 100644
--- a/userscript/novel-bookmark.user.js
+++ b/userscript/novel-bookmark.user.js
@@ -486,6 +486,12 @@
     return b.kind || "manga";
   }
 
+  // finished is a fact about the Series, decided from the owner's side and
+  // derived on the wire (issue #157); the panel only labels it.
+  function finishedLabel(b) {
+    return b && b.finished ? "Finished" : "";
+  }
+
   // ============================================================
   // Retry queue
   //
@@ -1306,6 +1312,7 @@
       el("div", { class: "meta" }, [
         el("a", { class: "go-t t", href: cont, text: b.title || b.series_id }),
         el("div", { class: "c" + (behind ? " behind" : ""), text: sub }),
+        b.finished && el("span", { class: "finished", text: finishedLabel(b) }),
         el("div", { class: "actions" }, [
           el("button", {
             class: "btn small star" + (b.favorite ? " on" : ""),
@@ -1594,7 +1601,7 @@
       --paper: #f2ece5; --paper-hot: #f0d3cb; --paper-dim: #ddd5cb;
       --mute: #8d857c; --mute-2: #5a5450; --faint: #3a3733; --faint-2: #57504b;
       --ember: #e0452c; --ember-wash: #1a1211; --ember-ink: #150907;
-      --ember-soft: #eda798; --brass: #b8912f; --trash: #6b5450;
+      --ember-soft: #eda798; --brass: #b8912f; --trash: #6b5450; --moss: #7fae86;
       --font-display: Georgia, "Times New Roman", serif;
       --font-mono: ui-monospace, SFMono-Regular, Menlo, monospace;
       --font-body: system-ui, -apple-system, sans-serif;
@@ -1720,6 +1727,12 @@
       font: 500 10px/1.4 var(--font-mono); letter-spacing: .12em; text-transform: uppercase;
     }
     .c.behind { color: var(--ember); }
+    /* finished: a Series fact, not a state class (issue #157) — same meta
+       typography as .c, moss instead of mute. */
+    .finished {
+      margin: 0; color: var(--moss);
+      font: 500 10px/1.4 var(--font-mono); letter-spacing: .12em; text-transform: uppercase;
+    }
     .actions { display: flex; gap: 0; flex-wrap: wrap; margin-top: 2px; }
     .btn {
       background: none; color: var(--mute); border: 1px solid var(--rule);
@@ -1763,7 +1776,7 @@
   // Exposes pure logic only — see userscript/test/novel-logic.test.js.
   // ============================================================
   if (typeof window === "undefined" && typeof module === "object" && module.exports) {
-    module.exports = { novelfull, lightnovelworld, anchorsFromHTML, statusOf, kindOf, maxChapter, escapeRe, computeLatestChapter, repairLnwStaleRow };
+    module.exports = { novelfull, lightnovelworld, anchorsFromHTML, statusOf, kindOf, maxChapter, escapeRe, computeLatestChapter, repairLnwStaleRow, finishedLabel };
   }
 
   // ============================================================
diff --git a/userscript/test/logic.test.js b/userscript/test/logic.test.js
index ff048f1..84971d8 100644
--- a/userscript/test/logic.test.js
+++ b/userscript/test/logic.test.js
@@ -58,6 +58,7 @@ const {
   anchorsFromHTML,
   statusOf,
   kindOf,
+  finishedLabel,
 } = require("../manga-bookmark.user.js");
 
 // detect() reads only these four properties off location.
@@ -397,6 +398,18 @@ test("statusOf defaults a missing status to reading", () => {
   assert.equal(statusOf({ status: "archived" }), "archived");
 });
 
+// ============================================================
+// finishedLabel — finished is a fact about the Series (issue #157), which is
+// the server's business; the panel only names it. The label is text through
+// the el() helper, never markup.
+// ============================================================
+
+test("finishedLabel names a finished series and nothing else", () => {
+  assert.equal(finishedLabel({ finished: true }), "Finished");
+  assert.equal(finishedLabel({ finished: false }), "");
+  assert.equal(finishedLabel({}), "");
+});
+
 // ============================================================
 // kindOf — a row written before the kind column existed has none, and every
 // one of those is manga.
diff --git a/userscript/test/novel-logic.test.js b/userscript/test/novel-logic.test.js
index 5471694..06fbd6c 100644
--- a/userscript/test/novel-logic.test.js
+++ b/userscript/test/novel-logic.test.js
@@ -49,6 +49,7 @@ const {
   kindOf,
   maxChapter,
   repairLnwStaleRow,
+  finishedLabel,
 } = require("../novel-bookmark.user.js");
 
 function loc(href) {
@@ -563,6 +564,23 @@ test("repairLnwStaleRow does not regress progress when the repaired-key row is a
   assert.equal(out.list[0].last_chapter_num, 100);
 });
 
+// ============================================================
+// Merge rank — exactly two values: archived beats reading, and nothing else
+// can ever win (issue #157 retired the finished bucket).
+// ============================================================
+
+test("repairLnwStaleRow merge keeps archived over reading and lets no third value win", () => {
+  const canonical = (over) => staleRow(Object.assign({ key: "lightnovelworld:immortality-simulator" }, over));
+  // archived beats reading whether it arrives as the stale row or the repaired one
+  let out = repairLnwStaleRow([canonical({ status: "archived" }), staleRow({ status: "reading" })], [], {}, lnwPage());
+  assert.equal(out.list[0].status, "archived");
+  out = repairLnwStaleRow([staleRow({ status: "archived" }), canonical({ status: "reading" })], [], {}, lnwPage());
+  assert.equal(out.list[0].status, "archived");
+  // "finished" is not a bucket anymore: a row carrying it reads as the
+  // default, so it can never win (issue #157).
+  out = repairLnwStaleRow([staleRow({ status: "finished" }), canonical({ status: "reading" })], [], {}, lnwPage());
+  assert.equal(out.list[0].status, "reading");
+});
 // ============================================================
 // kindOf
 // ============================================================
@@ -575,6 +593,18 @@ test("kindOf passes through novel", () => {
   assert.equal(kindOf({ kind: "novel" }), "novel");
 });
 
+// ============================================================
+// finishedLabel — finished is a fact about the Series (issue #157), which is
+// the server's business; the panel only names it. The label is text through
+// the el() helper, never markup.
+// ============================================================
+
+test("finishedLabel names a finished series and nothing else", () => {
+  assert.equal(finishedLabel({ finished: true }), "Finished");
+  assert.equal(finishedLabel({ finished: false }), "");
+  assert.equal(finishedLabel({}), "");
+});
+
 // ============================================================
 // Source guard
 //