What If on MSN

What would happen if we could open a portal to a parallel universe?

What if there are other universes, just like ours? With an infinite number of Earths? With uncountable versions of you? And ...
Screen Rant on MSN

Star Trek's mirror universe: A pioneering alternate reality

In the season 2 episode "Mirror, Mirror," Star Trek perfected the alternate universe trope long before Hollywood's multiverse ...