"Different versions of the same people," Tim says simply, offhand, like quantum variation is a simple fucking concept that just anyone would grasp after a time. It's not simple, per se - he doesn't understand it himself, nor does he think he could really get into the science of it, even if he really wanted to - but when you've met three versions of the same Boss Monster kid with three different histories, three different variations on the same theme, there's all sorts that you'll put aside to believe.

He shrugs, tiredly.

"It's been known to happen."