Mary Kate made a grab for my laptop, but I jumped out of my chair. Clutching my computer, I raced around our room, tripping over the motorcycle boots I’d left on the floor and hurdling over Mary Kate’s neatly stacked textbooks. I ran straight into the laundry line of bras I’d hung up to dry and got briefly tangled up, but I never stopped running and, as I ran, I turned the volume up louder:

‘DON’T STOP, JUST DO IT, DO IT …’

My room-mate was in hot pursuit, kicking off her fuzzy slippers, tripping over the hem of her bathrobe, crying out desperately, ‘Alex! They’re actually gonna hear!’

‘Good!’ I shouted over the music. ‘That’s the point!’

‘RIGHT NOW, LICK IT GOOD …’

‘It’s not just the Long Huggers! What about –?’

She didn’t even get a chance to speak the name aloud. But such is the power of this particular netherworld nuisance in a nun’s habit that she can materialize at the merest flicker of thought in your subconscious. It happened just as I was climbing to the top bunk, cackling triumphantly over the blaring music with a hot pink bra slung over my shoulder and Mary Kate, red-faced and furious, swatting at me with the belt of her bathrobe: the Knock of Doom at our door.

I immediately clapped my laptop shut. The music stopped. I looked at Mary Kate. She looked at me. We knew that knock – that icy, anal-retentive knock. It could only belong to one person.

And so, communicating silently with our eyes, we did an immediate silent inventory of the contraband in our room. My clove cigarettes were stashed in the hollowed-out pages of my theology textbook; the voodoo doll I’d made of Father Bray was in a winter boot in the back of my wardrobe. Other than that, everything looked normal: Mary Kate’s top bunk was neatly made, with her stuffed penguin, Sir Shackleton, propped up against the baby-blue pillows, and underneath, mine was a mess of sheets and dirty clothes and possibly Ancient Babylonian artefacts buried in there somewhere. So the coast was pretty much clear.

Mary Kate smoothed her braids, retied her robe and went to open the door. She welcomed our visitor in her best chipper, human-equivalent-of-an-American-Girl-doll voice: ‘Hi, Sister Hilda!’

Sister Hilda – or Sister Hellda as I fondly call her – is our dorm nun. Picture the Wicked Witch of the West if she ditched the striped tights, wiped off the green BB cream and rode a tornado to an all-girls’ dorm in Minnesota because one Dorothy to torture just wasn’t enough.

Oh, and did I mention she lives RIGHT NEXT DOOR to us?