Last Train to Doomsday (S02E05)

Thundarr, Ookla, and Ariel are hot on the trail of Janus, a mummy-like figure, after he and a band of hawk mutants launch an assault on villages and the train line operated by Tye, the ex-swamp urchin from "Harvest of Doom." The trio faces an unexpected twist when they discover that Janus is actually Gemini, the two-faced sorcerer from "Secret of the Black Pearl," plotting his revenge against Thundarr. Tye makes a comeback as a savvy train-driving entrepreneur, adding another layer to their adventure.