It is Monday morning, first period, and the class is quiet and absorbed. Perhaps they've spotted the head watching from the corridor? Or maybe the've all developed a headache? No, they are smiling, wearing the beatific look of the conscientious student. Unnerved, and starting to sweat, I ask one reasonably trustworthy soul why the group seems to have taken this mutual vow of industrious silence. He looks at me as if I have asked the most ridiculous question in the world. "Tonight's parents' evening, isn't it?" You know what it's like. Working too hard. You forget. But the pupils haven't - thoughts of the coming night's activities have paralysed them with fear.
Cast your mind back to your own schooldays. If you could nominate just one night as the worst of the year, which would it be? The annual disco, where you never managed to get intimate with the boygirl of your dreams? How about the school play, where perhaps, like me, you were forced to spend two hours every Christmas dressed as a tree? Scary stuff, but there's worse. These ordeals pale against the horror of parents' evening, and the chance of the teacher telling your parents something about you they don't already know.
Fifty minutes later and the class files out as if they are heading for the gallows. For a moment, I feel a twinge of sympathy - which quickly passes as I panic about my lack of preparation. I must prepare; I can't just sit there and improvise, can I? I mean, what can I say to them? You see, I have the paperwork, but I don't have the words.
As the day wears on, I think about nothing else. At lunch-time, I start to compile what I think will be an exhaustive set of notes, with an in-depth psychological profile of each child. During the rest of the day's lessons, I talk to pupils while imagining an older version of themselves sitting next to them.
How will I broach the subject of a child's academic problems? Come to think of it, how do you manage to keep talking for more than 10 seconds when a child is doing exceptionally well? Well Mrs Smith, I know young Thomas is top of the class, but do you know that he picks his nose? Sorry, but the truth hurts.
As the hour grows near, I decide the best possible policy is to be creative. I'm an English teacher, I pride myself on my ability to inspire and be inspired. In other words, I decide to make it up as I go along.
It is time. A quick check in the mirror and I am ready to meet my public. I feel nervous, the kind of heart-stopping, sweaty-palmed sensation people must feel just before they bunjee-jump.
The hall is quiet, just a few parents and children. I find my desk, sit down and look around.
I relieve a passing pupil of several Digestives and wait, munching nonchalantly as if I have done this a million times before.
Two minutes later and I am in the thick of it, giving an Oscar-winning performance, gesticulating wildly in front of two absorbed parents as I explain the merits of homework. They are listening, I am in control. Then comes the first bombshell, "So what grade will she get?" I search for a non-committal answer.
"All I can guarantee is that she will not fulfil her potential unless she keeps up her current high standard of work." Sorted that one out then.
Later, after using words like potential, commitment and attitude so much it feels as if I have been transformed into a politician, I watch the last family-pack stroll out of the gym. Tired and emotional, I crawl home.
The next morning I ask the class what their parents thought of the evening. One solitary hand goes up. "They said you were very nice, Sir." Nice.
Piece of cake, as they say.
Sahail Ashraf teaches English at Ashburton High School, Croydon, Surrey