An Alien who calls himself The Watcher contacts the Fantastic Four to warn them of an incoming doom - Galactus, a unique terrifying gigantic nearly indestructible alien humanoid who devours whole planets, is coming to feed on Earth.

The Skrulls may have been defeated, but they want revenge, so they send a superior genetically modified Srkull - Superskrull - to take down the Fantastic Four.