diff --git a/src/hqt/tui/screens/new_session.py b/src/hqt/tui/screens/new_session.py
index 2b43fd6..3ff3070 100644
--- a/src/hqt/tui/screens/new_session.py
+++ b/src/hqt/tui/screens/new_session.py
@@ -63,15 +63,20 @@ class NewSessionScreen(
                     "bubblewrap not found — run `hqt doctor`",
                     id="sandbox-warning",
                 )
-            yield Label("Filesystem access:")
-            yield Select(
-                [("Read-write", "rw"), ("Read-only", "ro")],
-                id="fs-select",
-                value="rw",
-                allow_blank=False,
-            )
-            yield Label("Network:")
-            yield Switch(id="net-switch", value=True)
+            # Sub-options of the sandbox switch: only meaningful when sandboxing
+            # is on, so hidden until then (mirrors the worktree -> branch reveal).
+            sandbox_options = Vertical(id="sandbox-options")
+            sandbox_options.display = False
+            with sandbox_options:
+                yield Label("Filesystem access:")
+                yield Select(
+                    [("Read-write", "rw"), ("Read-only", "ro")],
+                    id="fs-select",
+                    value="rw",
+                    allow_blank=False,
+                )
+                yield Label("Network:")
+                yield Switch(id="net-switch", value=True)
             with Horizontal(classes="dialog-actions"):
                 yield Button("OK", variant="primary", id="ok-btn")
                 yield Button("Cancel", id="cancel-btn")
@@ -89,6 +94,11 @@ class NewSessionScreen(
         else:
             branch_input.display = False
 
+    def on_switch_changed(self, event: Switch.Changed) -> None:
+        if event.switch.id != "sandbox-switch":
+            return
+        self.query_one("#sandbox-options", Vertical).display = event.value
+
     def on_button_pressed(self, event: Button.Pressed) -> None:
         if event.button.id == "ok-btn":
             self._submit()
diff --git a/tests/test_tui.py b/tests/test_tui.py
index 77b2111..f3582fb 100644
--- a/tests/test_tui.py
+++ b/tests/test_tui.py
@@ -1869,3 +1869,29 @@ async def test_poll_sessions_dispatches_due_prompts_and_notifies():
 
         mock_service.dispatch_due_prompts.assert_awaited_once()
         assert any("Prompt sent" in call[0] for call in notify_calls)
+
+
+@pytest.mark.asyncio
+async def test_sandbox_options_hidden_until_switch_on():
+    """The fs/net rows are sub-options of the sandbox switch: hidden until it is
+    turned on, shown when on, hidden again when turned back off."""
+    app = HqtApp()
+    async with app.run_test(size=(120, 40)) as pilot:
+        from hqt.tui.screens.new_session import NewSessionScreen
+        from textual.widgets import Switch
+
+        app.push_screen(
+            NewSessionScreen(["claude"], is_git_repo=True, sandbox_available=True)
+        )
+        await pilot.pause()
+        options = app.screen.query_one("#sandbox-options")
+        assert options.display is False
+
+        switch = app.screen.query_one("#sandbox-switch", Switch)
+        switch.value = True
+        await pilot.pause()
+        assert options.display is True
+
+        switch.value = False
+        await pilot.pause()
+        assert options.display is False