As Superman gives Blue Beetle, Firestorm, and Stargirl a tour of the Fortress of Solitude, they run afoul with General Zod, Faora, and an unidentified Kryptonian villain who are accidentally freed from the Phantom Zone. Now with Superman trapped inside, the three teen heroes must work together to stop the Kryptonian villains.

When members of the Justice League are affected by the Phantom Zone ray and become phantom-like, their only hope for freedom is to somehow get a message to Booster Gold.