It’s the first day of term tomorrow so I really ought to get an early night. But I can’t. Some mysterious force has directed me to my wine stash under the stairs and I find myself uncorking a second bottle in an attempt to ward off the panic welling up inside me. I phone Jane Fleming, a kindly sort from the science department, hoping for some reassuring words. Jane answers the phone sounding remarkably chipper, saying she’s never felt better. Then she explains that she resigned last week and has got a job at a call centre. She says the money’s about the same and her doctor is confident she’ll be off the tranquillisers by Christmas.

By 3am I’ve resorted to trash television. I’m staring at something called Rhodes to Ruin, a cable show about naughty Brits abroad; an inebriated, thong-clad couple are sitting astride a giant banana jet ski. A close-up of the man’s sagging backside triggers a moment of recognition, and I realise that it’s none other than Orlando Jones, our lecherous head of drama, and his wild-eyed female companion is Ramona Lynch - a sixth-former whose multiple exam failures must put her somewhere on the wrong side of 21. Once upon a time I would have been shocked, but after a year at St Brian’s the sight of a member of staff performing lewd acts on late-night TV seems rather tame.

The next morning I walk through the gates with a new palmtop computer (a present to myself), a box of vitamin C tablets and a restraining order against the deputy head.

Nigel Horsmel’s approach to my induction year was unorthodox. He was by turns a bully and a sex pest, a campaign that culminated in his scrawling obscenities about me in the staff toilet and then drunkenly begging me to marry him at the staff party. I got a court injunction prohibiting him from coming near my flat and requiring the school to install a security alarm in my classroom.

The mood in the staffroom is one of forced joviality, as colleagues wistfully describe idyllic holidays spent birdwatching and potholing on National Trust estates. I don’t mention my ouzo binge on Mykonos.

There is much discussion of Those Who Have Not Returned: Cynthia Thyme, the elderly technology teacher who’s now working as a private tutor in Colombia; Jane Fleming; and, of course, Judith Crock, my head of department, who is off sick.

I’m roused from my hangover by a young woman dressed in a neat white blouse and black chalkstripe trousers. “Hello, I’m Angel, Angel Montague.” Maybe she’s a sixth-former who forgot to collect her results. “Yes Angel, can I help?”

“I’m the new history NQT,” she says quietly. “Mr Horsmel said you’re the acting head of department.”

I’m trying to take in what she’s just said, when Horsmel appears at her shoulder. “Ah good, you’ve met. I’m sorry I wasn’t, um, permitted to contact you over the holidays, Miss Casement, as I had some important news.

Miss Crock is in hospital - had a nasty accident on her walking holiday in Bavaria.So you’re in charge. Good luck!”

“So sad about her dog dying,” sighs Angel, after Horsmel has gone. “Fell off a mountain chasing a rabbit...” The poor thing looks as though she might cry. No matter. It won’t take Angel Montague long to discover how deep the St Brian’s rabbit hole goes.

Next week: St Brian’s gets an adviser