diff --git a/README.md b/README.md
index e38dc3e..12df3ec 100644
--- a/README.md
+++ b/README.md
@@ -105,6 +105,7 @@ file / environment rather than relying on `.env`.
 | `/`                      | Main page with all videos categorized by camera view |
 | `/camera/<camera_view>`  | All videos for a single camera view                  |
 | `/video/<path:filepath>` | Streams a video file from the TeslaCam directory     |
+| `/refresh`               | Forces a re-scan of the TeslaCam directory           |
 
 ## Camera Views
 
@@ -119,6 +120,9 @@ file / environment rather than relying on `.env`.
 
 ## Notes
 
+- The directory scan is cached in memory for `SCAN_CACHE_TTL` seconds
+  (default 300) to avoid re-walking the tree on every request. Hit
+  `/refresh` to force a re-scan after copying new clips onto the drive.
 - Debug mode is off by default (`FLASK_DEBUG=0`) and is only used by the local
   dev server. It has no effect when running under a WSGI server like gunicorn.
 - The TeslaCam directory must be accessible from the machine running the app (e.g., a mounted USB drive or network share).
diff --git a/templates/index.html b/templates/index.html
index 12706f3..77db409 100644
--- a/templates/index.html
+++ b/templates/index.html
@@ -1029,18 +1029,31 @@
           }
         });
 
-        // Auto-play next clip when video finishes
+        // Auto-play next clip of the same camera when video finishes
         player.addEventListener("ended", function () {
-          const list = getFiltered();
-          const i = list.findIndex(function (c) {
+          if (!current) return;
+          // Build a list of clips for the SAME camera, sorted like the sidebar
+          const sameCam = clips
+            .filter(function (c) {
+              return c.cam === current.cam;
+            })
+            .sort(function (a, b) {
+              if (sortMode === "name")
+                return a.filename.localeCompare(b.filename);
+              const da = tsToDate(a.timestamp),
+                db = tsToDate(b.timestamp);
+              const ta = da ? da.getTime() : 0,
+                tb = db ? db.getTime() : 0;
+              return sortMode === "oldest" ? ta - tb : tb - ta;
+            });
+          const i = sameCam.findIndex(function (c) {
             return (
-              current &&
               c.cam === current.cam &&
               c.timestamp === current.timestamp &&
               c.filename === current.filename
             );
           });
-          if (i > -1 && list[i + 1]) playClip(list[i + 1]);
+          if (i > -1 && sameCam[i + 1]) playClip(sameCam[i + 1]);
         });
 
         render();
diff --git a/videoplayer.py b/videoplayer.py
index 179bd04..160bd03 100644
--- a/videoplayer.py
+++ b/videoplayer.py
@@ -11,6 +11,7 @@ play videos from different camera views.
 
 import os
 import re
+import time
 
 from dotenv import load_dotenv
 from flask import Flask, render_template, send_from_directory, abort
@@ -39,8 +40,15 @@ CAMERA_VIEW_MAPPING = {
     'right_pillar': 'Right Pillar'
 }
 
+# In-memory scan cache. Scanning a large TeslaCam tree on every request is
+# expensive, so the result is cached and only refreshed after this many seconds
+# (or when /refresh is hit). Override via the SCAN_CACHE_TTL env var.
+SCAN_CACHE_TTL = int(os.environ.get('SCAN_CACHE_TTL', '3600'))
 
-def scan_teslacam_videos():
+_scan_cache = {'data': None, 'expires_at': 0.0}
+
+
+def _scan_teslacam_videos_uncached():
     """
     Recursively scans the TeslaCam directory tree for video files and categorizes
     them by camera view.
@@ -84,6 +92,22 @@ def scan_teslacam_videos():
     return videos_by_camera
 
 
+def scan_teslacam_videos(force_refresh=False):
+    """
+    Returns the cached TeslaCam video scan, refreshing it when the TTL expires
+    or when `force_refresh` is True. Safe to call on every request.
+    """
+    now = time.time()
+    if (
+        _scan_cache['data'] is None
+        or now >= _scan_cache['expires_at']
+        or force_refresh
+    ):
+        _scan_cache['data'] = _scan_teslacam_videos_uncached()
+        _scan_cache['expires_at'] = now + SCAN_CACHE_TTL
+    return _scan_cache['data']
+
+
 def get_camera_display_name(camera_view):
     """Returns human-readable title for a camera view key."""
     return CAMERA_VIEW_MAPPING.get(camera_view, camera_view.replace('_', ' ').title())
@@ -137,6 +161,16 @@ def serve_video(filepath):
     return send_from_directory(TESLACAM_DIRECTORY, filepath)
 
 
+@app.route('/refresh')
+def refresh():
+    """
+    Forces a re-scan of the TeslaCam directory, bypassing the cache TTL.
+    Useful after copying new clips onto the drive.
+    """
+    scan_teslacam_videos(force_refresh=True)
+    return 'Cache refreshed', 200
+
+
 if __name__ == '__main__':
     # Local dev server. For production, run behind a WSGI server instead, e.g.:
     #   gunicorn -w 4 -b 0.0.0.0:5000 'videoplayer:app'