“Right. It means small events can have large, whatchamadingit, ramifications. The idea is that if some guy kills a butterfly in China, maybe forty years later—or four hundred—there’s an earthquake in Peru. That sound as crazy to you as it does to me?”
It did, but I remembered a hoary old time-travel paradox and pulled it out. “Yeah, but what if you went back and killed your own grandfather?”
He stared at me, baffled. “Why the fuck would you do that?”
That was a good question, so I just told him to go on.