[ Oh good, now he's feeling nauseous on top of that headache. That's just what he needs. ]

Could be. [ His voice creaks a little. ]

But... we don't know if that's how, uh, time travel even works.

[ Greg's no quantum physicist, but he has read a lot of sci-fi novels. He taps a finger against the paper, drawing imaginary lines splaying out from the crossed line. ]

There could be infinitely branching timelines, each still intact after divergence?