Whatever Happened to the Man of Tomorrow? is the final storyline appearing in the main Superman comic books prior to the Crisis on Infinite Earths. The story details Superman's last stand against Mr. Mxyzptlk and a number of other villians at the Fortress of Solitude. However, this story contradicts the events depicted in the Crisis, perhaps showing what would have happened to the Superman of Earth-1 if the universes had not been combined into New Earth.