In order to rescue a fellow agent, West and Gordon infiltrate the prison on Devil's Island, West by taking the place of a prisoner and Gordon by gaining employment as a guard. The prison's commandant is Gustave Mauvais, a cruel, vindictive man whose beautiful wife, Camille, is desperate to escape from his clutches.
Tropes present in this episode:
- Distant Duet: Jim and Artie, one in the pit and the other in the commandant's waiting room, are shown simultaneously singing "Old Master Jip," a folk song which ends up being used as an identification code throughout the episode.
- Identical Stranger: In the tag scene the Girl of the Week introduces our heroes to her fiancé, who is played by Theodore Marcuse, the same actor who played the episode's Big Bad/her husband and was last seen sinking in quicksand.
- Leaning on the Fourth Wall: In one scene Artie whistles along with the background music, which is a tune featured in previous episodes as part of the series' library, but never diegetically. Which implies that Artie can somehow hear the soundtrack.
- Obfuscating Insanity: Le Fou, whom the agents believe is insane from prolonged captivity and talk freely around. Turns out he's a spy in the commandant's employ.
- Shave And A Haircut: This is how Artie signals his readiness to exit the Chamber of Togetherness. The background music chimes in when he gets to the final two beats.
- Spy Speak: The various agents identify themselves to each other by singing "Old Master Jip." Additionally, Artie carries a watch which plays the tune, as does the agents' ally on the island; contact is made by using them as sign/countersign.
- Trojan Prisoner: A slightly more convoluted version than normal, with Jim impersonating an actual convict in order to get inside the prison without arousing suspicion and Artie getting himself hired as a guard rather than just posing as one.