In an isolated mansion deep in a far away forest, the super-villain known as the Wizard has invited Medusa, the Sandman and the Trapster. He tells them that they must work together as a team in order to defeat the Fantastic Four, and that they will be called the Frightful Four. Back at the Baxter Building, the Fantastic Four are alerted to a jewellery store robbery and leave to deal with it. Herbie detects the presence of the Wizard and his new team, and they carefully prepare to deal with this new menace. Reed and Sue deal with the Wizard and Medusa while Ben and Herbie are left to stop the Trapster and the Sandman. Not properly prepared to deal with the Frightful Four, the Fantastic Four are out of their depth and the Wizard's new team manages to escape from them. As the Fantastic Four have to deal with their very public defeat, the Frightful Four begin to argue among themselves before the Wizard tells them to follow his new plan. They lure the Fantastic Four to a bank, where they begin to fight among themselves as a result of one of the Wizard's spells. During the fracas, Medusa kidnaps Herbie. After the spell has worn off, the Wizard challenges the Fantastic Four to rescue their comrade from his mansion. At the Wizard's mansion, they have to survive the many traps and liberate their friend as well as ensuring that the Frightful Four are defeated for good.