Suddenly the door bursts open and Gavin Gunner enters. He farts loudly, laughs to himself and then spots me at the front of the room. "Oh, sorry, Miss. It's me new medication. Keeps me calm but I get the runs really bad!"
Slowly, the room half-fills with Gavin's colleagues from 10C. It's not a bad turn-out for the first day, really. It's certainly better than last autumn when the entire class skived off because Nadia from Big Brother was doing a personal appearance at the local Mr Burger franchise.
Pupils aren't the only people in short supply at St Brian's today. In the staffroom at break time I'm staring out of the window, transfixed by the vapour trails left by planes jetting off to exotic holiday spots.
St Brian's has 22 Antipodeans on staff, and none of them has turned up for work today. Melbourne Mick phoned in to say he'd be back after the Test match had finished, but the supply agency hasn't heard from the others. As the deputy head, Nigel Horsmel, pins the cover sheet to the noticeboard, his victims curse their workmates from down under. Horsmel just smiles.
"Now come on, everyone! There are always winners and losers in the global marketplace!"
Most of the Aussies and Kiwis had disappeared before the last day of last term. A wise move.
That Friday was, in keeping with St Brian's tradition, a "dress-down day".
The kids see this concession as a pre-holiday gesture of goodwill, but its main function is to prevent them being identified by their school colours in the inevitable late-afternoon shopping centre riot. As the children arrived, all hoods, baseball caps and crop tops, the head, Alastair Scarlett, stood beaming. "The police will never pick them out wearing this clobber!" Ramona Lynch, from Year 13, tottered over to me at the gate, her boots unfeasibly high and skirt microscopic, to show me the Christmas present her fiance had bought her: a fake diamante necklace that spelt the word "bitch".
The main excitement of the day was provided by the Christmas panto, directed, as always, by Orlando Jones, head of drama and the most longstanding member of staff to be placed on capability assessment by the senior management team. The production, Lemony Scarlett and a Series of Unfortunate Events, passed without serious incident, although the consensus is that Orlando has lost his edge since the LEA started sending a legal observer to monitor his plays.
Staring at the cover sheet, and the three double lessons I've been allocated with 10C in a 40-year-old mobile classroom on a freezing January day, I begin to have some sympathy for the plight of the modern satirist.
Next week: The year of the love rat.Charity Begins: Adventures of an NQT, Charity Casement's diary of her first year at St Brian's, is available from TES Books, pound;2.99. Tel: 0870 444 8633 or visit the TESBookshop at www.tes.co.uk