Spike hears that someone matching Julia's description has been spotted on Callisto, one of Jupiter's frozen moons, and takes off from the Bebop without telling anyone. Faye, annoyed at being left behind, follows after him. Spike arrives in the desolate, snow-covered settlements and heads to a blues bar, where he meets Gren—an androgynous saxophone player with mysterious connections to Spike's past. Meanwhile, Vicious is also on Callisto, on the run from the Red Dragon Syndicate after they turned against him for his unauthorized actions.
Spike and Gren have a tense conversation, and it turns out Gren has a history with Vicious from the Titan War, where he was subjected to experimental drugs that changed him physically. Faye ends up at the same bar through her own misadventures, and the paths of all the characters start converging on the frozen moon. The episode ends on a cliffhanger as Spike realizes the connection between Gren and Vicious, and Vicious himself appears, setting up the confrontation to come in Part 2.
See also: Session 13: Jupiter Jazz (Part 2), Spike Spiegel, Faye Valentine