Oh, sure, it's simple enough when you travel back in time to, say, kill Hitler. But time travel rapidly becomes a confusing jumble of alternate realities and versions of people who are not always what they seem.
In their song "I Am Alone," the band They Might Be Giants tries to unravel events as a time traveller encounters multiple versions of himself, all of whom are armed and trying to kill specific alternate versions for the good of the world.
Or are they?
-via Laughing Squid