After Cosmic Boy's mother dies from injuries sustained in a bombing, he goes after the men responsible.
Cosmic Boy learns about the death of his parents and is full of rage. He rushes into space to find the spacecraft holding the killers and teach them a lesson, but before Cosmic Boy does something he regrets, Night Girl stops him. Cosmic Boy relives his past, how he became a founder of the Legion of Super-Heroes, and finds that he has a duty as a son, and not a Legionnaire. He rushes off to find the killers again. Meanwhile, Chameleon Boy is pardoned for his crime of treason but finds that he has lost his power to shapeshift. The Legion arrive in time to see Cosmic Boy confront the killers, but they do not stop him. They realize he has to face them on his own terms and he does. He realizes he can't kill them because that's not what his parents want and he simply walks away.