About fifteen years ago there had been an accident at a bio research lab located in my town and various viruses had gotten out. At the time everyone thought that it had been contained and everything was safe, but a few years later, a few people had mutated. It only effected about one in twenty and only targeted guys, but the results were consistent; at the onset of puberty, the guy would grow an extra torso and pair of legs. For the most part he'd become female except he kept his male genitalia...at least between his rear legs, between the forelegs he was all girl.
I had been one of the (un)lucky ones who'd contracted the virus, and was now legally a girl.
I stared at the stone, dumbfounded.