It’s the longest night of the year. Not the winter solstice, but presentation evening. As we arrive for our 20-hour day, we are directed to the hall where the atmosphere is tense ahead of the coming battle. The head, Dr Alastair Scarlett, is briefing staff, flanked by his deputy, Nigel Horsmel.

“We have two entrances, here and here,” says Scarlett, as Horsmel points at a huge map of the school that’s taped to a wall. “John Baller and the girls from the lunchtime team will be stationed at the gym doors.” Baller, head of maths and union rep, nods sternly. John might spend most of the year fighting the senior management, but this is one night when everyone pulls together.

Blaine Harrington, our new advanced skills teacher, will be working the front-of-house crowd with Tiziana Fausti, sex goddess of the media department, and Amy Studds, the office vamp. Someone wolf-whistles. “Ooh, we’ll be like Charlie’s Angels,” squeals Amy. Blaine smooths down his blond highlights and squeezes Amy’s arm playfully. So it’s muscle out the back and eye candy up front.

Those of us who don’t have either a black belt in judo or a modelling contract are to mingle with the mob and pile in at the first sign of trouble. “We’ve got credible information that the unit kids from last year might be planning some kind of stunt,” says Scarlett.

Students and parents start to arrive and soon the hall resembles a convention of the Britney SpearsDestiny’s Child appreciation society: piercings, belly and cleavage as far as the eye can see. The boys wear low-slung trousers and hoodies advertising bands with names like Megakill and Carnal Force.

The senior management team trudges up to the stage and Scarlett introduces the guest speaker. St Brian’s doesn’t have any famous former pupils (at least none that are currently at liberty), so it is left to Oriel Grier, our LEA adviser, to attempt to put a gloss on yet another round of dismal exam results. She begins by hailing the three passes in the new GNVQ baggage handling course as the beginning of a new era for St Brian’s but is soon drowned out by a cacophony of mobile phone ringtones and text message beeps.

I’m beginning to drift off when I catch sight of John Baller gesticulating wildly from the side of the stage. Behind him is the delinquent wing from the recently departed Year 11. The kids have breached Scarlett’s ring of steel and trouble is looming. Horsmel tries to defuse the situation with a joke. “Oh look, it’s the cast from I Know What You Didn’t Do Last Summer,” he announces, but no one laughs. Then the familiar and comforting scent of rolling tobacco wafts across the room and Wendy the support co-ordinator appears. The boys capitulate immediately. Whether it’s the memory of their experiences in the behaviour unit, or the sight of Wendy in yellow polyester slacks rather than her regulation dungarees, I don’t know. But for the rest of the evening the intruders sit silent as their peers honour the achievements of the past year. This doesn’t last long.

At the conclusion of our annual celebration of school life, there’s a dash for the 13 Horseshoes, which is soon heaving with 16-year-olds necking lager. When a slightly pissed lad confides that he used to fantasise about having sex with me, I decide it’s time to leave.

One evening gone and, under the new pension proposals, just 39 to go.

Next week: Man trouble - again