Imagine, you're on your ride to work when a man starts talking about how he's going to build a time machine. Then, suddenly he's interrupted by someone who looks just like him. He claims to be from the future and says that the time machine can't be built.

You're thinking it has to be a joke, when another future person runs in, then another, both talking to present people that look just like them. Could this be real?

This was the latest prank from Improv Everywhere. They used 4 sets of identical twins to make it happen. Watch how it all played out.