Dr. Doom manages to transfer his mind into Reed's body by hacking his consciousness. Reed, who is now trapped in Dr. Doom's body, must now figure out a way to return to his friends and family, or else Dr. Doom will destroy the Fantastic Four and several city blocks by transforming the Baxter Building into his new weapon

Reed stands accused of purposefully exposing Susan, Johnny and Ben to the cosmic rays that have transformed them into the Fantastic Four. While they're distracted by this turmoil, Dr. Doom strikes!

Fellow scientist and friend Bruce Banner comes to Reed looking for help. But his dark secret is soon revealed - he's the Incredible Hulk! When Banner reverts to his giant green alter-ego and goes on a rampage across New York City, the Fantastic Four must stop him

Upon returning from a mission, the team finds their neighbors in the Baxter Building much more friendly than usual, but it soon becomes clear their "neighbors" are shape-shifting aliens - the Skrulls!

Reed's miniaturization experiment malfunctions, shrinking the team and putting them at risk when H.E.R.B.I.E. incorrectly identifies them as vermin and tries to exterminate them

Things take a turn for the worse when Johnny gives his friend Frankie an unauthorized tour of Reed's lab. When Frankie is sucked into another dimension, Johnny goes in after her to prevent anyone from finding out. But as he does so, a small bug comes through the dimensional portal. Susan, Ben, and Reed now have to deal with the bug, while Frankie and Johnny are trapped in the other dimension

Namor the Sub-Mariner arrives with a decree banning humankind from the oceans. Susan and Johnny go underwater to negotiate, but are taken prisoner in Atlantis. Ben and Reed must fight their way through sea monsters and Namor to save their teammates

Alicia's stepfather and artist, Phillip, gets hold of a piece of the Reed's space station and the irradiated metal gives him the ability to control the minds of others through miniature clay statues

When Reed recall one of his deep-space probes, it brings back with it the Impossible Man. The Fantastic Four must find a way to get rid of the annoying imp before his antics become dangerous