Showing an orange playhead sweep without touching the audio was a lie — the music kept playing forward. Now the reel's audio track splices in reverse(the preceding seconds) through the reverse window, so the waltz audibly runs backward while the scope sweeps back. Verified: the window's loudness envelope is the exact time-mirror of the source segment, bucket-for-bucket. Because areverse flips the segment, the reversed part starts on the exact sample the forward playback just left — no click at the entry. The seam at the far end is masked by the scene's cut to the end card. Timing moved to land AFTER the VO says "reverse playback" rather than at the phrase's start: the beat now begins at ~28.5s, as "holding spacebar" is spoken. REVERSE_START/END are hoisted so the keymap frames, the audio splice and the timing all read from one place. Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>