I stand, arms folded, by the door. Speaking calmly, I say: "We are on nine minutes now. You know you have to be quiet before you go into my lessons.
If it gets to 10 minutes, I will fetch your head of year and you will all do a half-hour detention." (No they won't, I think to myself). "No we won't!" yells one boy, near the back of the line. "You can f*ck off!"
Is that kid telepathic?
No, he can't read books, let alone minds.
However, just in case, I form a mental image of me strangling him.
It seems to work: there's a moment of quiet.
Right, that'll do. Seize the moment, like a drowning man grasping at a passing branch.
"OK, in we go. Remember, coats on hooks." They like to keep their coats on at every opportunity, regardless of the ambient temperature, as they provide useful places to conceal things like crisps, phones and spliffs.
I remain in the doorway so that they can only go in one by one.
They push and shove each other, or pull on each other's bags and coats, completely oblivious to my presence.
I glare at my watch. We've wasted 10 minutes already. There is nothing unusual about this. It's a scene that's being repeated all over the school, although usually inside a classroom.