‘Mary Kate!’ I called over the fire alarm, which was ringing in my brain now and driving me crazy. ‘They won’t FIT in our clothes! And, even if they did, don’t you think someone is gonna notice that Dominic is an enormous hairy beast in a plaid skort? I mean, the kid is six-four. How is he POSSIBLY going to blend in? It’s not like there’s a bunch of GIRLS walking around our hallway who are six foot …’

It dawned on me and Mary Kate at the exact same moment. When our eyes met, this insane smile stretched across her face, like we were Marie and Pierre Curie and we’d just decided to blow up radium for the first time. Pat and the Toothless Beast – Dom – kept looking back and forth, wide-eyed, from Mary Kate’s insane smile to me. I was terrified.

‘We can’t!’ I told Mary Kate.

But already she was hopping determinedly across the sticky floor, snatching something off her desk on the way. She opened the door (the alarm blared even louder) and scuttled one-legged out into the hallway – and I had to follow.

A confused mass of yoga-pant and pajama-clad girls were shuffling towards the door, covering their ears against the alarm and blinking in the flashing emergency lights. They were obediently evacuating. But Mary Kate limped her way forcefully through the crowd, pushing people aside, and walked straight up to the door of the room we had always dreaded: room 102.

It belonged to the Rowers.

‘We can’t!’ I was still protesting over the wailing siren. ‘They’ll kill us! They will literally kill us. They almost killed you already, and you hadn’t even stolen their shit!’

‘They’re not here,’ she said rapidly, trying the handle. The door was locked. ‘Read the whiteboard.’

Out of town for Springfield varsity regatta read the message board on their door. Back Sunday after bedchecks. Go, SM Crew!

‘How did you know that?’ I asked Mary Kate.

‘I keep the crew schedule in my planner so I know which weekends are safe to go down to the laundry room.’

She had stuck an eyebrow brush (that’s what she’d grabbed off her desk) in the door handle and, with an impressively expert series of turns, jiggles and clicks, she picked the lock. The door swung open.

I stood gaping in the doorway. But Mary Kate was already inside, recklessly yanking open drawers and wardrobe doors. When she found what she was looking for, she held them aloft above her head in triumph: two grey varsity sweatsuits, size XXL.

‘Mary Kate! That’s stealing!’ I said in astonishment and admiration, my ears ringing now from shouting over the alarm. ‘You just broke into their room and stole their shit!’

‘Good!’ Mary Kate cried, whirling around with savage joy flashing in her eyes. ‘They broke my friggin’ nose – it’s about time I got my revenge!’