diff --git a/crates/engine/src/cmd/browse.rs b/crates/engine/src/cmd/browse.rs
index 45fc19bb5..01c67c267 100644
--- a/crates/engine/src/cmd/browse.rs
+++ b/crates/engine/src/cmd/browse.rs
@@ -158,7 +158,11 @@ fn stamp_browsed(s: &mut Session, root: &str, files: &[String]) {
 /// referred to by an undo / redo step.
 fn in_use(s: &mut Session) -> std::collections::HashSet<PhotoId> {
     let mut keep = held(s);
-    keep.extend(s.visible().iter().copied());
+    // Missing Photos lists library photos only, never Local records, so it keeps nothing here; and
+    // working it out checks every original (minutes on a sleeping NAS when the library opens on it)
+    if s.source != crate::LibrarySource::Missing {
+        keep.extend(s.visible().iter().copied());
+    }
     keep
 }
 
diff --git a/crates/engine/src/library.rs b/crates/engine/src/library.rs
index 32ad1da53..a5071b4b3 100644
--- a/crates/engine/src/library.rs
+++ b/crates/engine/src/library.rs
@@ -558,7 +558,10 @@ impl Session {
             self.selection.ids.retain(|id| self.catalog.photo(*id).is_some());
             self.selection.active = self.selection.active.filter(|id| self.catalog.photo(*id).is_some());
         }
+        // not on Missing Photos: working that view out checks every original (minutes on a
+        // sleeping NAS), and the app checks them in the background once it runs
         if self.selection.active.is_none()
+            && self.source != LibrarySource::Missing
             && let Some(first) = self.visible_cloned().first()
         {
             self.selection = Selection::single(*first);
diff --git a/crates/engine/src/tests_forget_local.rs b/crates/engine/src/tests_forget_local.rs
index 229b262a0..9f5d1f572 100644
--- a/crates/engine/src/tests_forget_local.rs
+++ b/crates/engine/src/tests_forget_local.rs
@@ -259,3 +259,58 @@ fn browsing_again_forgets_untouched_records_of_deleted_files() {
     assert_eq!(s.catalog.to_snapshot(), expect);
     let _ = std::fs::remove_dir_all(&root);
 }
+
+/// Opens `lib` with a probe that counts the originals it checks.
+fn open_counting(lib: &Path, clock: &Arc<Mutex<String>>) -> (Session, Arc<std::sync::atomic::AtomicUsize>) {
+    let checks = Arc::new(std::sync::atomic::AtomicUsize::new(0));
+    let mut s = Session::new().with_fs();
+    let c = clock.clone();
+    s.clock = Box::new(move || c.lock().unwrap().clone());
+    let n = checks.clone();
+    s.media.availability.set_probe(Arc::new(move |p| {
+        n.fetch_add(1, std::sync::atomic::Ordering::SeqCst);
+        Path::new(p).exists()
+    }));
+    s.open_library(lib, false).unwrap();
+    (s, checks)
+}
+
+/// A library last shown on Missing Photos opens without checking its originals: that view holds
+/// no Local records, so forgetting them needn't work it out, and no photo is picked from it (each
+/// check can wait for a sleeping NAS; a big library on one froze the window for minutes).
+#[test]
+fn opening_on_missing_photos_checks_no_originals() {
+    let root = temp_dir("missing");
+    let (a, lib) = (root.join("a"), root.join("lib"));
+    for i in 0..5 {
+        png(&a.join(format!("m{i}.png")), i);
+    }
+    let clock = Arc::new(Mutex::new("2026-08-01T10:00:00".to_string()));
+    let mut s = open(&lib, &clock);
+    s.execute("library.import", &json!({"paths": [a.to_string_lossy()], "mode": "add"})).unwrap();
+    s.execute("library.source", &json!({"kind": "missing"})).unwrap();
+    // every original is there: the view is empty and nothing is selected
+    assert!(s.visible().is_empty());
+    assert!(s.selection.active.is_none());
+    s.close_library().unwrap();
+    drop(s);
+    let (s, checks) = open_counting(&lib, &clock);
+    assert_eq!(s.source, LibrarySource::Missing, "the view is restored");
+    assert_eq!(checks.load(std::sync::atomic::Ordering::SeqCst), 0, "opening an empty Missing view checked originals");
+    assert!(s.library.as_ref().unwrap().forgot_local.is_some(), "forgetting still ran");
+    drop(s);
+
+    // the originals go: the view lists them, one is active
+    std::fs::remove_dir_all(&a).unwrap();
+    let mut s = open(&lib, &clock);
+    s.execute("library.source", &json!({"kind": "all"})).unwrap();
+    s.execute("library.source", &json!({"kind": "missing"})).unwrap();
+    assert_eq!(s.visible().len(), 5, "all five are missing");
+    assert!(s.selection.active.is_some());
+    s.close_library().unwrap();
+    drop(s);
+    let (s, checks) = open_counting(&lib, &clock);
+    assert_eq!(s.source, LibrarySource::Missing);
+    assert_eq!(checks.load(std::sync::atomic::Ordering::SeqCst), 0, "opening a full Missing view checked originals");
+    let _ = std::fs::remove_dir_all(&root);
+}