Then, rather than saying anything I'd scan their faces until someone wouldn't be able to stay quiet any longer. I think to add to the atmosphere they'd all be wearing 1920s costumes and we'd have swapped the Specsavers look for pince-nez and lorgnettes.
"What is it? Has something terrible happened?" It would be Susan Chard, usually cynical and sour, but now sounding rather impressed by my meaningful silence.
"Yes, Susan. I'm afraid I have some bad news. But of course, someone here might know that already. And soon I'll be able to reveal exactly who that is."
Then I'd spin round and look piercingly at someone else, probably the Buff, or that woman who does supply and eats biscuits whenever she isn't talking.
"You see, there's been a robbery." There would be a big gasp - one of those huge, theatrical intakes of breath. Of course, if anyone gasped like that in real life you'd be telling the ambulance crew to bring the defibrillator, but here we've got dramatic licence.
And, by the way, wouldn't it be great if you could buy a dramatic licence the way that you can a television licence. It would let you really exaggerate and no one would be allowed to criticise.
But back to my Poirot moment. "Yes, a robbery. We've lost a laptop." And I'd hold up an empty laptop carrying case, the way that you might hold up an empty picture frame when an old master has been stolen.
Of course, getting a piece of equipment nicked isn't really so exciting.
You go to look for it one day and it's not there.
I'd gone to get the laptop I'd been using as a reserve for the whiteboards and it wasn't there. I couldn't even be precisely sure when it was taken.
There hadn't been a break-in and there was no obvious damage to the lock-up cupboard. But the laptop was gone.
Everyone we've spoken to has given us the same profound piece of wisdom. It happens. Expensive stuff, in a place full of people, gets stolen. It happens in offices, it happens in hospitals and it's happening in schools.
The head, Mrs Gatsby, immediately started talking about CCTV cameras and monitoring equipment and then went into her own Miss Marple routine, talking about an "inside job".
But there are so many possibilities. It was someone who knew the layout of the school so that narrows it down to all the teachers and classroom assistants, caterers and cleaners, pupils, parents and families, ex-pupils, their friends and anyone who has ever carried out any work there. Which means that just about anyone, including me and Mrs Gatsby, is in the frame.
But this is going to be something that we're going to have to think about for the future. Primary schools haven't been targets for robberies in the past because they haven't had anything worth taking. There isn't much demand for overhead projectors in the local pub.
Now people realise that we have a growing store of shiny new equipment and when it comes to laptops, portable means nickable. And schools have been designed to be open, welcoming places, and are not easy to secure.
It also raises questions about how we leave laptops around the school and how we protect them at night. And does it mean we should scrap any plans to allow children to take equipment home?
Or else you start getting suspicious. You think about the parents helping out after-hours, or that conversation you had with the music teacher about how much she owed on her credit card.
"So you thought it was the perfect crime, Mrs Gatsby?"
"Yes, and I'd have got away with it if it hadn't been for those pesky kids."
Everyone get ready for a big Scooby-Doo ending.