When they conscripted me, I was classified as a Human Mutation, third category. Or a hum-three in the vernacular. The hum-ones are the nonviables: stillborns and infant deaths and living veggies. We got millions of 'em. The hum-two's are viable but useless, all the guys with extra toes and webbed hands and funny eyes. Got thousands of them. But us hum-threes are the elite, so they tell us. That's when they draft us. Down here, inside the Graham Project bunker, we get new names. Old Charlie Graham himself used to call us his "timeriders" before he croaked, but that's too romantic for Major Salazar. Salazar prefers the official government term: G.C., for Graham Chrononaut. The orderlies and grunts turned G.C. into geek. The killer geeks, we called ourselves. Six litlte killer geeks riding the time stream, biting the heads off vast chickens of probability. "Under Siege" is a science fiction time travel story told on two audio CDs.