I'd had so many plans, just before I went back. I was prepared to an insane degree. I'd spent days camping in the wilderness, gathering enough iron to create a goddamned magnet. I'd memorized the fundamentals of aviation, chemistry, nuclear physics. I knew all there was to know about rebuilding civilization.

And it had all slipped away, one memory after another, fading into a blur, after I'd fallen through the time vortex.

So here I am, trying to explain to some neolithic ignoramus how to make gunpowder. The most I can remember is that it requires a mixture of sulfur, charcoal and potassium nitrate. Sulfur is easy to find, charcoal not much harder, but the only way I can think of to get potassium nitrate is from urine or something, and Caveman is looking at me like I'm telling him to take a piss in a bucket and leave it out in the sun, which is more or less what I'm doing.

I became the village idiot, essentially. And the worst part of it all is that I can't even carve a decent wheel from stone. I hate the past.