Doomsday's origin is revealed as Zod and Lis-Ser probe the creature's memories. Brainiac forces Seg to take him to the Fortress, but Seg comes up with a way to remove Brainiac's presence from his brain.

Zod brings Doomsday to heel and unleashes him on the Rebels, and Seg, Val, and Kem fight a last-ditch battle to hold the creature back while their compatriots escape.