Part 2 of 2, continued from LEGION OF SUPER-HEROES (1989 4th Series) #73. Legionnaire twins Live Wire and Spark battle their mad older brother, leaving one of the siblings critically injured. Plus, Brainiac 5 returns with a secret.
Spark and Live Wire face their brother Mekt, the Lightning Lord. Live Wire loses his arm in the battle. Meanwhile, some Legionnaires travel into the past to speak with Superboy so they can figure out a way to save Valor in the future.