"The OFSTEDers are here," he announces. "Have you seen their cars, sir? There's a Merc, a Porsche, a BMW and some P reggies. There must be more money in this OFSTED game than in teaching, sir."
Matthew has also taken the trouble to peer through the conference room windows. He now reports a sighting of "four women and five blokes in there". In fact, an unlucky 13 inspectors are joining our comprehensive for the week.
Along the corridor I think I spot one - a large man in a smart new grey suit, nervously sporting a gardenia buttonhole. On closer inspection he turns out to be our deputy head. I've got a feeling nothing will seem familiar this week - unreality dawns.
TUESDAY: Unreal? Surreal is the word I need. Yesterday there were chocolate bars in the staffroom pigeon holes; today it's plums. A scoreboard announces that there will be a bottle of champagne for the teacher who is inspected the most, a contest unfair to ordinary class teachers like me. The head of music will walk it - his inspector seems to be about to claim squatters' rights on the music room.
The staffroom is our sanctuary, a no-go area for OFSTEDers, which is just as well as on the noticeboard is several square metres of scurrilous anti-OFSTED propaganda.
By the end of the day I have been inspected twice. My inspector, a pleasant elderly lady, reminds me of one of my primary school teachers who always wore a hat and wellington boots, chain-smoked Woodbines, and did little but read Charles Dickens to us.
WEDNESDAY: Bananas in the pigeon holes, a less than subtle reference to the mental health of some staff. All reports of the "feedback" appear positive, but that doesn't stop the worry.
Another lady inspector appears for my afternoon registration period. I am reading class extracts from their essays, some moderately funny. To my relief, I catch her giggling behind her handbag. As I leave the staffroom at the end of the day one colleague, normally placid and reserved, is hurling books, papers and tea cups across the room, laughing hysterically.
THURSDAY: Penguins - the chocolate biscuits - are perched in the pigeon holes today.
My inspector enters for the first lesson of the day and takes a seat at the back of the room. "Oh," I say, "I'm sorry but you can't sit there, that's Geoffrey's place." Flustered, she removes herself to the desk I allocated to her on her first visit and I sense a psychological advantage. By midday there's a feeling of relief. Feedback to the heads of departments is good.
FRIDAY: There are no posh cars in the car park and the conference room is in darkness.
Carnations and lollipops greet us - and tubers, believed to be of an OFSTED cactus which sprouts deadly prickles every four years.
The week has forced us all to reflect on what we are doing and why and, since it is clear we shall receive a good report, the inspection may also deliver a welcome boost to morale. But I'm also aware that I'll never own a Merc or a Porsche.
Marcus Short writes under a pseudonym and lives in the West Country.