Fantastic Four (1961) 162-A

"The Shape of Things to Come!"

Both Reed Richard's meld together mentally so they can share information on what is unfolding around them. They learn that this is a concentrated effort to bring all three worlds to war and destruction by one man, Arkon. Knowing what is going on, the FF combines their efforts to stopping the war as they first stop the alternate Earth from being invaded by Johnny and the 5th Dimension. Then Reed, on the original Earth, confronts Mr. Devoor and learns how to get to Arkon and sends the Thing after him while Johnny and the alternate Reed, try to get the alternate Earth to stand down.