The Powerpuff Girls and the Crystal Gems teamed up to save the world from a new threat that's coming to Earth. As for Butterfly, she has found herself a new friend who's the last hope to save the universe.

The power-hungry, malicious magician Hex uncovers a spell that channels the power of the Crystal Gems into him. With his newly gained powers Hex becomes capable of casting a curse so vast that sends everyone into oblivion while granting him to keep his. Together, the Powerpuff Girls and Steven must join forces to break the curse and save the day.

When the Powerpuffs accidentally go too fast in another race, they once again create a wormhole. However, this hole in space transports them to Beach City, where they meet the Gems. However, Mojo, Him, and the Homeworld Gems find out about this. The three villains form an alliance to destroy the heroes... The Gems and the PPG must team up to end evil once and for all.