The Frightful Four have arrived to destroy the Fantastic Four. They take control of Ben's mind to turn him against the team. Can the Fantastic Four overcome this threat? And who exactly is Medusa?

Gorgon is searching for Medusa to return her to the mysterious Great Refuge. Johnny is forced to help her, but Gorgon captures her. The Fantastic Four discover his hideout and find the Inhumans.

The Inhumans teleport back to the Great Refuge, but Johnny is teleported there too after jumping in after Crystal. The rest of the team try to find him, while it is learned Black Bolt's evil brother, Maximus, has taken over.

The Black Panther attacks and lures the Fantastic Four to Africa. They find the Black Panther is leader of an African tribe and that they are under attack by the master of sound, Klaw.

Bruce Banner is in town, which means the Incredible Hulk is too. When the Hulk goes on a rampage, Ben gets in his way.

Sue insists the team get some R, but Johnny stays at home. The others head to Tee Vu island, which is home to a Kree Sentry. Meanwhile, Black Bolt destroys the negative barrier and frees the Inhumans, reuniting Johnny and Crystal.