The Fantastic Four prepare to travel to the moon so that Reed can conduct experiments with his new rocket fuel derived from a meteor that struck the Earth in Siberia. In the Soviet Union, scientist Ivan Kragoff conducts the final stages of training for his three apes. He plans to subject the three and himself to the same cosmic rays that the Fantastic Four did except he plans on doing so without any form of protection.
On the way to the moon the Fantastic Four see the Soviet spaceship and the Torch goes over to investigate. Kragoff and the three apes now have super powers. One of the apes uses telekinetic powers to hurl the Torch back to his ship. The Soviets escape to the moon.
Upon landing on the moon, the FF learn that there was once a civilization there. Upon scouting around the Thing is set upon by the apes and Kragoff. However, the Watcher steps in and stops the scuffle. He will have no one disturb the moon which is his vantage point to watch the Earth. It is his job to keep on eye on the inhabitants of Earth just as it is his race's job to watch all civilizations across the universe. The Watcher will allow only this one battle for the moon - the Soviets represented by Kragoff and the apes and the Americans represented by the FF.
The Soviets make quick work of the FF and capture Sue. Kragoff cages off the apes and locks Sue up as well. Kragoff goes off to set traps knowing the other three will soon arrive. Sue sets the apes free which then tear into the food in the same room. The FF capture Kragoff but he escapes with the help of the apes. However the apes having been fed are not at his mercy and they forcefully move him away in escape. The Watcher bids farewell telling the FF that he must move from the moon now that humans have been to the moon but he promises he will always be watching.