"Back to Earth" continues, guest starring the Fantastic Four! As the team descends into the earth, they are attacked by new unexpected enemies! Who are they? What are they doing under Monster Island? And what's really going on with those seismic readings?

Summary
Down in the caverns under Monster Island, the Fantastic Four and the Silver Surfer plan to follow the seismic readings to the source of the problem. They are then ambushed by a group of Skrulls. They are defeated and tell the heroes that they are stranded with no way to communicate with empire. They were on a mission to detain watch an Inorganic Technotroid, a advanced nearly indestructible fighting machine.

The Surfer and the Four realize that this menace must be taken care of and begin to search for it. Once they find the Technotroid it begins to attack them. It is as impressive as the Skrulls claimed. The Surfer manages to do some damage to it before the Ant-Man reprograms it from the inside. Ant-Man repairs the Skrulls communication equipment so they can call home and the heroes continue on their mission.