William had managed not to be ill, somehow, in spite of the gore and the stench of rotting and burnt flesh and the fact that he could see things like brains no longer inside skulls and there was blood spattering his shirt. That was actually the minor part, because there was blood spattered everywhere. He thought the lack of violent physical reaction meant he was probably in shock, but it also meant that he could keep moving, so he wasn't going to question it too closely.
He hadn't been able to stop doing headcounts, and he was aware that he was being utterly useless at things like finishing off any completely-crippled survivors or herding students back to their Houses, but his brain wouldn't stop counting. He saw Elsie being carried by one of the older Slytherin girls, looking paler than he would have liked, but still alive. He counted every Ravenclaw even though it didn't mean anything, because he couldn't remember now who was in the Tower and there were almost certainly still students scattered all over the school. He mentally checked off every one of his colleagues. Nate. Spencer, Mikey. Gerard, Jon, Adam. Pete. Gabe.
Gabe. William didn't even think before he was turning in the direction of the doors, picking up speed slightly and nearly tripping over what had once been a House-elf as he zeroed in on the one person he hadn't heard from throughout this entire nightmare, who had somehow miraculously managed to stay alive.