Maximus the Mad takes on the Fantastic Four…and all of humanity! Crystal seeks permission from her Inhuman family to join the FF in full membership. But upon arriving in the Inhumans' Hidden Land, the team is attacked by Alpha Primitives!

Maximus the Mad has enslaved the Inhumans, and has sent out his minions to bring back the remaining member of the royal family, Johnny's love Crystal, who has been residing with the FF for some time. Unfortunately for his plans, although the Alpha Primitives capture Crystal, they also bring back the Fantastic Four with them!

The group battles against Maximus the Mad's robot soldier Zorr before the self appointed ruler unveils his greatest weapon- a long range Hypno-Gun, which will emit its rays over the entire world!