diff --git a/README.md b/README.md
index 8f2b77b..e3b4eee 100644
--- a/README.md
+++ b/README.md
@@ -4,7 +4,8 @@ A small desktop application for Debian that treats a directory of markdown files
 as an ordered manuscript.
 
 * **Left pane** — every `*.md` file in the workspace directory, in a manual order
-  you set by **dragging the `⠿` handle** up and down.
+  you set by **dragging the `⠿` handle** up and down. **Hover a file** to see its
+  `# Slug:` line as a tooltip — a handy one-line synopsis of each chapter.
 * **Right pane** — a markdown text editor for the selected file (optional live
   preview via the *Preview* checkbox).
 * **Order + contents are saved and version-controlled with git.** The order lives
diff --git a/src/app.rs b/src/app.rs
index 9e98d71..4200a33 100644
--- a/src/app.rs
+++ b/src/app.rs
@@ -74,6 +74,10 @@ pub struct App {
     /// Each file's word count captured when the workspace was opened, used as the
     /// per-file baseline for the "this session" delta.
     session_start_counts: HashMap<String, usize>,
+    /// Cached `# Slug:` value per file (name -> slug) for the file-list hover
+    /// tooltip. Filled when the workspace opens and refreshed on save; the
+    /// selected file is read live from the buffer instead.
+    slugs: HashMap<String, String>,
     /// Grammar/spelling issues from the last LanguageTool check.
     lt_matches: Vec<crate::langtool::Match>,
     /// The exact buffer text the current `lt_matches` were computed against;
@@ -159,6 +163,7 @@ impl App {
             repo_root: None,
             pending_repo: None,
             session_start_counts: HashMap::new(),
+            slugs: HashMap::new(),
             lt_matches: Vec::new(),
             lt_checked_text: String::new(),
             lt_status: String::new(),
@@ -216,6 +221,7 @@ impl App {
         self.pending_delete = false;
         self.clear_lt();
         self.session_start_counts = self.snapshot_counts();
+        self.slugs = self.snapshot_slugs();
         if !self.files.is_empty() {
             self.select(0);
         }
@@ -289,6 +295,19 @@ impl App {
             .collect()
     }
 
+    /// Read every file and return its `# Slug:` header value (only for files that
+    /// have one), for the file-list hover tooltip.
+    fn snapshot_slugs(&self) -> HashMap<String, String> {
+        self.files
+            .iter()
+            .filter_map(|name| {
+                let text = std::fs::read_to_string(self.path_for(name)).unwrap_or_default();
+                let header = crate::preprocess::parse(&text, &self.config.draft_marker);
+                header.slug.map(|slug| (name.clone(), slug))
+            })
+            .collect()
+    }
+
     fn persist_order(&self) {
         let _ = order::write_order(self.workspace(), &self.files);
     }
@@ -321,12 +340,26 @@ impl App {
     fn save_current(&mut self) {
         if let Some(idx) = self.selected {
             if self.dirty {
-                if let Some(name) = self.files.get(idx) {
-                    let path = self.path_for(name);
+                if let Some(name) = self.files.get(idx).cloned() {
+                    let path = self.path_for(&name);
                     match std::fs::write(&path, &self.buffer) {
                         Ok(_) => {
                             self.dirty = false;
                             self.status = format!("Saved {name}");
+                            // Keep the hover-tooltip slug cache in step.
+                            let slug = crate::preprocess::parse(
+                                &self.buffer,
+                                &self.config.draft_marker,
+                            )
+                            .slug;
+                            match slug {
+                                Some(s) => {
+                                    self.slugs.insert(name, s);
+                                }
+                                None => {
+                                    self.slugs.remove(&name);
+                                }
+                            }
                         }
                         Err(e) => self.status = format!("Save failed: {e}"),
                     }
@@ -412,6 +445,7 @@ impl App {
                         self.files.remove(idx);
                         self.titles.remove(&name);
                         self.session_start_counts.remove(&name);
+                        self.slugs.remove(&name);
                         self.persist_titles();
                         self.persist_order();
                         self.selected = None;
@@ -463,6 +497,9 @@ impl App {
                 if let Some(words) = self.session_start_counts.remove(&old_name) {
                     self.session_start_counts.insert(new_name.clone(), words);
                 }
+                if let Some(slug) = self.slugs.remove(&old_name) {
+                    self.slugs.insert(new_name.clone(), slug);
+                }
                 self.persist_order();
                 self.status = format!("Renamed to {new_name}");
             }
@@ -1288,6 +1325,15 @@ impl App {
                         for idx in 0..self.files.len() {
                             let name = self.files[idx].clone();
                             let selected = self.selected == Some(idx);
+                            // The selected file's slug is read live from the
+                            // buffer (so unsaved edits show); others come from the
+                            // cache filled on open/save.
+                            let slug = if selected {
+                                crate::preprocess::parse(&self.buffer, &self.config.draft_marker)
+                                    .slug
+                            } else {
+                                self.slugs.get(&name).cloned()
+                            };
                             let row = ui
                                 .horizontal(|ui| {
                                     ui.dnd_drag_source(
@@ -1299,13 +1345,14 @@ impl App {
                                             );
                                         },
                                     );
-                                    if ui
-                                        .add_sized(
-                                            [ui.available_width(), 20.0],
-                                            egui::SelectableLabel::new(selected, &name),
-                                        )
-                                        .clicked()
-                                    {
+                                    let mut label = ui.add_sized(
+                                        [ui.available_width(), 20.0],
+                                        egui::SelectableLabel::new(selected, &name),
+                                    );
+                                    if let Some(slug) = &slug {
+                                        label = label.on_hover_text(slug);
+                                    }
+                                    if label.clicked() {
                                         clicked = Some(idx);
                                     }
                                 })