diff --git a/README.md b/README.md
index c7fe2ba..68d6f87 100644
--- a/README.md
+++ b/README.md
@@ -73,10 +73,10 @@ Optional, add these later if you want them:
 Pull the prebuilt image onto your Docker host:
 
 ```bash
-docker pull git.kretzer.club/andrew/alembic:0.6.8
+docker pull git.kretzer.club/andrew/alembic:0.6.9
 ```
 
-That is the whole install. You do not need to download the source or build anything. The `0.6.8` is the version; you can pin to it so nothing changes under you, or use `latest` to always get the newest.
+That is the whole install. You do not need to download the source or build anything. The `0.6.9` is the version; you can pin to it so nothing changes under you, or use `latest` to always get the newest.
 
 (If you would rather build it yourself from source, you can, but you do not need to.)
 
@@ -136,7 +136,7 @@ Create a file called `docker-compose.yml` on your server (put it wherever you ke
 ```yaml
 services:
   alembic:
-    image: git.kretzer.club/andrew/alembic:0.6.8
+    image: git.kretzer.club/andrew/alembic:0.6.9
     container_name: alembic
     ports:
       - "8420:8420"
diff --git a/pipeline/lib/export-laptop-playlists.py b/pipeline/lib/export-laptop-playlists.py
index 52ab5d7..906f99a 100755
--- a/pipeline/lib/export-laptop-playlists.py
+++ b/pipeline/lib/export-laptop-playlists.py
@@ -57,11 +57,12 @@ OUT_DIR = f"{_MUSIC_DATA_DIR}/playlists-laptop"
 # Absolute Windows path to the laptop's library root.
 LIBRARY_LAPTOP_ROOT = r"C:\Music\Library"
 
-# Beets stores paths with this prefix (the container-side mount of the
-# library); strip it to get the path relative to the library root. This is
-# still "/music/" through the migration's Stage 0-3 transitional mount;
-# revisit at Stage 4 once beets' directory: becomes MUSIC_DATA_DIR/Library.
-BEETS_LIBRARY_PREFIX = "/music/"
+# Prefixes beets may display library paths under, tried in order: the real
+# library dir (everything since the 2026-07-08 path rewrite) and the legacy
+# transitional mount (any stale pre-rewrite entry). Strip whichever matches
+# to get the path relative to the library root; when neither matches the
+# track is outside the library and is skipped.
+BEETS_LIBRARY_PREFIXES = (f"{_MUSIC_DATA_DIR}/Library/", "/music/")
 
 M3U_EXT = ".m3u"
 # Older formats from earlier iterations of this script — swept by reconcile.
@@ -157,9 +158,12 @@ def build_beets_index() -> dict[tuple[str, str], list[tuple[str, str, str, str]]
         if len(parts) != 4:
             continue
         aa, alb, ti, path = parts
-        if not path.startswith(BEETS_LIBRARY_PREFIX):
+        rel = next(
+            (path[len(p):] for p in BEETS_LIBRARY_PREFIXES if path.startswith(p)),
+            None,
+        )
+        if rel is None:
             continue
-        rel = path[len(BEETS_LIBRARY_PREFIX):]
         idx.setdefault((_normkey(alb), _normkey(ti)), []).append((aa, alb, ti, rel))
     return idx
 
diff --git a/pipeline/lib/fix-track-metadata.py b/pipeline/lib/fix-track-metadata.py
index a2e89d2..cf08dba 100755
--- a/pipeline/lib/fix-track-metadata.py
+++ b/pipeline/lib/fix-track-metadata.py
@@ -49,8 +49,10 @@ _ALEMBIC_CONFIG_DIR = os.environ.get("ALEMBIC_CONFIG_DIR", "/config")
 _MUSIC_DATA_DIR = os.environ.get("MUSIC_DATA_DIR", "/data/music")
 
 LIBRARY = f"{_MUSIC_DATA_DIR}/Library"
-# Still "/music" through the migration's Stage 0-3 transitional beets mount;
-# revisit at Stage 4 once beets' directory: becomes MUSIC_DATA_DIR/Library.
+# Legacy prefix from the migration's transitional beets mount. Since the
+# 2026-07-08 path rewrite beets displays real LIBRARY paths, so this only
+# matters for accepting pasted /music/... paths as input and as a fallback
+# beets query form for any stale pre-rewrite DB entry.
 CONTAINER_PREFIX = "/music"
 SPOTIFY_ENV = f"{_ALEMBIC_CONFIG_DIR}/pipeline/_spotify.env"
 SPOTIFY_GENRE = f"{os.environ.get('PIPELINE_DIR', '/app/pipeline')}/lib/spotify-genre.py"
@@ -316,15 +318,19 @@ def resolve_input_path(arg):
 
 
 def beets_id_for(host_path):
-    cp = host_to_container(host_path)
-    r = subprocess.run(
-        ["beet", "ls", "-f", "$id|||$path", f"path:{cp}"],
-        capture_output=True, text=True, check=True)
-    for line in r.stdout.splitlines():
-        if "|||" in line:
-            id_str, p = line.split("|||", 1)
-            if p == cp:
-                return int(id_str)
+    # Real path first (how beets displays everything since the 2026-07-08
+    # path rewrite), legacy /music/... form second for any stale entry.
+    # Querying only the legacy form (the old behavior) matched nothing after
+    # the rewrite, so retag-from-url silently skipped beet update/move.
+    for cp in (host_path, host_to_container(host_path)):
+        r = subprocess.run(
+            ["beet", "ls", "-f", "$id|||$path", f"path:{cp}"],
+            capture_output=True, text=True, check=True)
+        for line in r.stdout.splitlines():
+            if "|||" in line:
+                id_str, p = line.split("|||", 1)
+                if p == cp:
+                    return int(id_str)
     return None
 
 
diff --git a/pipeline/lib/replace-with-better.sh b/pipeline/lib/replace-with-better.sh
index 376a672..9234c5e 100755
--- a/pipeline/lib/replace-with-better.sh
+++ b/pipeline/lib/replace-with-better.sh
@@ -195,7 +195,18 @@ while IFS= read -r -d '' new_file; do
   existing_id="${match%%$'\x1f'*}"
   existing_container="${match#*$'\x1f'}"
 
-  existing="${MUSIC_DATA_DIR:-/data/music}/Library${existing_container#/music}"
+  # beets displays real ${MUSIC_DATA_DIR}/Library/... paths since the
+  # 2026-07-08 path rewrite -- use them as-is; only a legacy /music/...
+  # display path still needs the prefix swap. Blindly prepending (the old
+  # behavior) doubled the prefix, so every match logged [stale-db], the MP3
+  # never got replaced, and the leftover-import step at the bottom imported
+  # the staged FLAC as a NEW track -- producing exactly the flac+mp3 twins
+  # this script exists to prevent.
+  if [[ "$existing_container" == /music/* ]]; then
+    existing="${MUSIC_DATA_DIR:-/data/music}/Library${existing_container#/music}"
+  else
+    existing="$existing_container"
+  fi
   if [[ ! -f "$existing" ]]; then
     echo "[stale-db]       beets has $existing_container but file missing" | tee -a "$LOG"
     continue