The Frightful Four join forces to defeat the Fantastic Four, using the Wizard's machines to brainwash the Thing into switching sides.

The Human Torch pursues Medusa, only to stumble into her relatives, the Royal Family of the Inhumans. The Inhumans mistake the Fantastic Four for enemies.

The Fantastic Four journey to Attilan and assist the Royal Family in restoring Black Bolt to the throne, but must contend with Black Bolt's treacherous brother Maximus and the swarms of Inhumans loyal to him.