Photocopying rooms are dangerous places. There’s usually only one door, which means if the wrong person spots you pounding your fists on the machine while muttering oaths about toner and jammed paper, then, like the A4, you’re stuck. They won’t go away. They’ll pretend they can help when they know they can’t, or stand sneering at your ignorance of collating codes. If you’re really unlucky you’ll get cornered by the staffroom weirdo who just wants a bit of company.

Someone like Gabriel Mooney, a rogue RE teacher who operates off-curriculum at the periphery - some might say lunatic fringe - of his department.

Gabriel, fast approaching 50, began his teaching career in the 1970s on a commune in Devon before moving on to become a spiritual adviser in Amsterdam and Thailand. He often returns to visit his “fallen flock”; in fact he spends most weekends in the Netherlands, and during July and August supervises a summer school in Bangkok. It was while engaged in this extracurricular missionary work that he met Orlando Jones, head of drama at St Brian’s, and now Gabriel’s soulmate.

They weren’t big on police checks in the early 1990s, when Gabriel joined St Brian’s. He had a PGCE and a pulse, so he was in. A cursory investigation would have revealed a string of dismissals and dropped charges relating to his attempts to recruit pupils to his Shepherds and Sheep cult. The truth only came out in the run-up to the Millennium, when Gabriel barricaded himself in a science lab with a Year 8 group. The kids were having a great time until he turned the gas taps on and started brandishing a copy of the Bible. He had almost finished reciting the Book of Revelations, telling the kids the final battle was about to begin as he waved his cigarette lighter, when he was overpowered by a police armed response team.

But Gabriel returned. Somehow he convinced the General Teaching Council that his visions were stress-related and they recommended he go back to work on a reduced timetable.

I’ve been warned to avoid Gabriel during Lent. His take on the retreat into the wilderness with Jesus usually involves booking himself into a drug and alcohol rehabilitation centre for a fortnight. But this year he’s on the loose. “Hello, Sister Casement,” he says and I can sense him advancing towards the photocopier. I spin round. “Not now, Mr Mooney, I’m really not in the...”

Gabriel is wearing a long white robe with a blue shawl over his head.

“Listen, Charity. You probably think I want to seduce you, but I don’t, I want to convert you.”

“Why are you dressed as the Virgin Mary?” I demand, surprised by my outrage. “You look like something off a gay pride march. Just because you’ve blessed a few girls in Bangkok doesn’t mean there are going to be any second comings round here.”

Gabriel starts to snivel, so I take him back to his office, treading carefully round the crucifixes, statues and bleeding hearts that are scattered everywhere.

“Have I done something to offend you, Charity?” he asks. “I’ll make it up to you, please let me! I’ll take you to the pictures.” I’m weakening. I feel sorry for the poor man. “Well, I suppose it can’t hurt. What’s on?”

“Um, do you like Mel GibsonI?”

Next week: The customer is always right!