Leon nodded sympathetically, but Oli didn’t seem to care. ‘Boo-hoo,’ Oli said. ‘My mum died when I was three. What good’s sobbing her head off gonna do?’

Oli’s words made Leon and Daniel think about their mother dying of cancer. At the other end of the hallway, Abigail’s slender frame unlocked a door and hopped into a small room with a shower cubicle at the back.

‘You wanna mess with Little Miss Tearful?’ Oli asked.

Leon wasn’t keen. ‘We could put a different game on.’

But Oli was on his feet. After stepping into the hallway and taking a few furtive glances, he hurried to Abigail’s room, rattled her door and found that she’d had the sense to lock it. Undeterred, Oli beckoned Leon and Daniel.

‘You wanna see something funny?’ Oli asked.

The twins dashed along the hallway towards room nine. They instinctively wanted to tell Oli to leave Abigail alone, but their mission was to find out whether Oli would make a decent CHERUB recruit and they’d get a better sense of his personality if they went along with his plan.

‘I’ll give her something to cry about,’ Oli grinned, as he reached inside his tracksuit pocket and pulled a twenty-pence piece.

The boys heard water running as they closed up to the door of the shower room. A key with a big yellow In Use tag was in the outside of the door, which was locked with a bolt on the inside. This bolt had a bypass, which looked like a giant screw head and was designed to enable staff to access a bathroom from outside in an emergency.

Oli put his coin in the bypass slot and turned it to release the bolt. He looked back at Leon and Daniel, flicking one cheeky eyebrow before charging the door.

The door burst inwards. Abigail screamed as Oli reached into the steamy space and flicked out the light. Oli charged into the little cubicle and gave Abigail an almighty shove through the shower curtain. As she slammed tiles at the back of the shower and lost her footing, Oli scooped her towel and clean clothes from a shelf, whipped the curtain open and threw them all under the running water so they got soaked. As Abigail screamed in pain and shock, Oli backed out of the room and turned the key, leaving his victim screaming in pitch darkness.

‘You snitch and I’ll come after you,’ Oli warned, as he thumped on the door.

Abigail kept screaming as Oli turned back towards the twins, grinning like a loon.

‘How cool was that?’ he shouted.

Three hours later, the hallway was down to a bluish glow of nightlights as Daniel stepped out of his room. Abigail could be heard sobbing a few rooms away and a couple of kids were playing music, even though it was headphones only after ten on a weeknight.