When a returning astronaut turns out to be a powerful alien, Superboy and Krypto head off into space to investigate. They discover that the real astronaut has been kidnapped. Superboy is attacked by the aliens and imprisoned. The aliens plan to use him as a power source for an invasion of Earth. Krypto manages to rescue Superboy and the two of them put a stop to the aliens' plans.
A small sun appears near Earth which causes sever electrical problems. Superboy destroy the small sun and head off into space to investigate. They discover a planet whose inhabitants are at war. The call Superboy their king and tell him that the suns are the weapons of their enemies. Superboy and Krypto head off and destroy the weapon that is making the suns.