‘Goodnight,’ he says with a normal voice. He turns away from them and tries to listen to his own breathing instead of the muffled whispers and giggles. If only his ability to conjure his mother’s voice was dependable. Tonight he can magic no comfort from her at all. He hears the spring and bounce of Martin getting into bed, but doesn’t open his eyes. When Matron comes to check on them, he pulls the blanket up high over his chin.

A gentle tap on his hand a few minutes later makes him jump. Martin is kneeling at his bedside, looking intently at him.

‘Give it ten minutes,’ he mouths, holding up his two hands, all digits splayed and white in the dark. William stares back, as Martin returns to his bed and lies still under the covers.

He counts groups of sixty, but he must have drifted off because he’s pulled back to himself by a tap on his arm. Martin is at his side again, white-striped pyjamas glowing. Carefully he is folding his blanket into a long thin column.

‘Bed crawl revenge,’ he whispers.

Like a surfer paddling out into the sea, Martin propels himself forward, under William’s bed, his big body positioned neatly along the length of the blanket, not making a sound. William hangs over the bed and watches Martin glide under and out and under and out of the beds to his left, surprisingly graceful. William can no longer see him, so he lies back down and waits in the thick quiet of communal sleep.

A series of sudden, sharp raps make William start, followed by the squeak and groan of bedsprings. Then a creepy, twisted moan: ‘Charles. Charles.’

‘Who is it? Pack it in.’ Charles’s voice is high-pitched with false bravery.

‘Get William’s pyjamas.’ Martin’s distorted voice is louder now.

‘I can’t!’ Charles snaps. ‘We widdled on them.’

‘Get them. Put them on.’

‘No!’

There’s a sudden movement and a cry of pain. ‘Ouch! I’ll tell Matron.’

‘If you’re not back in bed wearing William’s pyjamas in thirty seconds, I’ll tell Matron what you did.’ Martin has given up on the voice.

‘I can’t! It’s disgusting.’

There’s another soft thud followed by a yelp. ‘Imagine being expelled for pissing on someone’s pyjamas. You’d go down in school history. Go! Now!’

Appalled, William lies rigid. Charles jumps up and runs the length of the dorm. The bathroom light pings on; a quiet slap, drips, the rasp of wet fabric pulling against skin, muffled grunting. The room hums with the silence of waiting, listening boys. When Charles scurries past, tiny and scrawny in oversized, drenched pyjamas, William fights the urge to apologise.

‘And if you tell anyone about this,’ Martin says, emerging easily from under the next bed to William, ‘I’ll come tomorrow night. And the next.’