The Thing and Mr. Fantastic are in the lab at the Baxter Building, watching on a viewscreen Ben curing an earlier version of himself. Reed is showing Ben this to demonstrate his new theory, that Ben did not travel back in time and create an alternate universe when he did that, but rather that he travelled sideways and visited an alternate universe, one which had already existed and which would have continued moving forward in time after Ben left.
Reed leaves, and Ben decides he'd like to see what that alternate world would have been like if he had been cured, so he powers up the "time machine", and heads off to visit the alternate world, but this time in the modern day...
The alternate world is an apparent disaster area. Buildings are ruined, and nothing is growing anywhere. Ben makes his way out of the powerless Baxter Building to the apocalyptic surface, where he's promptly attacked by a dozen people mistaking the Thing for "one of them". Ben shakes them off easily, and soon meets.. himself.
The two adjourn to a subway tunnel, where the alternate Ben tells our Ben his post-Thing life story. He opened his own bar, Spider-man took his position in the FF, and things were going well until Galactus showed up, killed all the superheroes, and sucked the planet dry. The alternate Ben is just mentioning how things were starting to recover, albeit slightly, until they discovered that "he" was back, when the two are suddenly attacked by a swarm of blue synthetic men. The two are separated, and our Ben is overpowered and captured.
The alternate Ben rallies the populace of the area to help him recover "our" Thing, while our Ben wakes up to find himself prisoner of... the Red Skull.