West and Gordon are investigating the theft of governmental copper and kerosene, but in the process get mixed up with the kidnapping of two women by a gang of outlaws whose base is apparently a fiery pit out in the mountains. Barbara Bosley, one of the kidnapped women, manages to escape after being forced to make suits for the men out of strange, silvery, fire-resistant cloth. She tells the agents that the man in charge is none other then John Brown of Harper's Ferry - who's supposed to be dead.
Tropes present in this episode:
- Back from the Dead: John Brown - or so he'd like everyone to think. He's actually his nephew.
- The Cavalry: The good guys invoke this; the bad guy attempts to subvert it. Artie escapes, goes for the cavalry and then rides back with them to save the day. Unfortunately, this was all part of Brown's plan - he intended to decimate the men as a demonstration of the effectiveness of his new cannon. Jim stops him.
- Dead Person Impersonation: Brown does his best to convince everyone that he is the John Brown, returned from the grave. His men apparently buy it.
- Historical-Domain Character: John Brown. Though it turns out to actually be the original's identically-named nephew.
- Impostor Forgot One Detail: Carma, the daughter of the leader of the outlaws working with John Brown, sees through Artie's disguise as an Irish peddler of drink when she recognises him by his ears (as an artist, she's very observant - she encountered Artie before, and the ears are the only things you can't disguise).
- Man on Fire: How Brown meets his end. Jim hurls a barrel of gunpowder at the cannon and Brown catches on fire in the subsequent explosion.
- Trail of Bread Crumbs: Artie gives Jim a pouch of powder which can be (and is) used to leave a trail which can be followed later.