he Science lesson is just starting as you arrive. The teacher is a tall thin bearded man with glasses. He’s calling the roll. You’re just in time to answer your name as you hurry to your seat.

‘Now,’ he says, when the roll is finished. ‘I want to make a few very important points about the Science course this year. Firstly, safety in the laboratories. Let’s start with the Bunsen burners. The gas emitted by these burners is both toxic and inflammable. This means that . . .’

Suddenly he’s interrupted by the crackle of static from the loudspeakers.

‘Teachers, please excuse this interruption,’ a voice says. ‘Could the following students please be sure to pick up their photographs from the office: Vanessa Hong, Steven Cooper, Martin . . .’

‘Bloody hell!’ the teacher says. ‘What a waste of time, having to listen to this.’

You’re shocked. The teacher swore! Here’s a person who’s done something wrong. You feel a powerful desire to report him to the nearest teacher, straight away. You rush out of the lab, ignoring the startled looks of the Science teacher, and of the students. Next door there’s an elderly man wearing a tweed sports coat, teaching a group of senior students.

You run straight in to his class.

‘Excuse me! Excuse me!’ you yell. ‘Our teacher just swore.’

The man stares at you with his mouth open. For a long time he doesn’t speak. The students stare at you, too, with their mouths open. Finally the teacher says something.

‘I think you’d better come with me.’ He takes you into a small office.

‘Now,’ he says. ‘Is this right? You want to report a teacher for swearing?’

‘Yes!’ you insist. ‘Yes! I have to report him.’

‘Why do you have to?’ he asks.

You think long and hard. You have a vague feeling that the Principal’s got something to do with it. But should you tell this man?