His fist hits Julius in the chin and something comes loose from his mouth, a tooth, apparently, a black, rotten molar that jumps from his lips like a coughed-up sweet. There is blood, too, and more Smoke, Smoke that pours from Julius’s skin, so black and pure it stoppers Thomas’s anger.

Immediately, Julius gains the upper hand. More than two years older, stronger, he flips the shorter boy. But rather than hitting him, he bears down with his whole body, embraces him, clings to him, rolls him into the lamp until it tips and smothers its own light. All at once Thomas realises what Julius is doing. He is rubbing his Smoke into Thomas, and Thomas’s into himself. Later, he will claim he was sullied by his attacker; that he himself remained pristine all through their fight. Now, in the darkness, he takes Thomas’s throat and squeezes it until Thomas thinks that surely he must die.

Julius lets go, judiciously, the moment the other boys have stepped close enough to get a better picture. He gets up, wipes at his shirt, and makes a show of his composure. Thomas, crumpled, remains on the floor. Only Charlie bends down to him, soothes him, and helps him back to the dorm.

CHARLIE

There is just one thing you can do against Soot if you don’t have any lye and that’s to soak it in urine. It’s disgusting, I know, but there’s something in piss that makes it fade. And so Thomas and I sneak back into the bathroom later that night when everybody is gone, put Thomas’s shirt into one of the bathtubs (the one used by Julius when he deigns to bathe), drink pints upon pints of water from the tap, and take turns peeing on it. Destroying the shirt is out of the question. They’d know at once: all items of clothing are carefully catalogued. It’d get Thomas expelled without appeal.