"The Parallel" is episode 113 of the American television anthology series The Twilight Zone. In this episode an astronaut returns from a voyage to find the world not quite the same as he remembers it. It was an early example of the concept of mirror or alternate universes. The Star Trek: The Original Series episode "Mirror, Mirror" was another example, although the differences between the characters in the two Star Trek alternate universes were quite noticeable. The concept has also been used by both DC Comics and Marvel Comics in their comic books and cinematic universes.