I am having an affair with your wife." Brett's words seep across the classroom like a slick of black bile. I smile at him politely and urge him vainly to look at the story we are trying to read.
He sits in my class, a 14-year-old impenetrable cloud of hatred, muttering an endless stream of threats and insults. "Your wife hates you. She told me. Your son hates you. I sell him drugs."
Everything he says or does is designed to provoke a response. He wants to control you through your reactions. A detention or another futile phone call home merely confirms that Brett is in control. He continues his endless muttered provocations in a low-frequency rumble.
Brett is deeply troubled. It is impossible not to feel sorry for him. You can sense his envy and unhappiness. But being with him makes you feel soiled.
When you are with Brett you wonder what purpose your job serves. In his case it is not about education. He rejected education some time ago. All we appear to be doing is keeping him within the fairly enclosed environment of school, to stop him doing greater damage elsewhere. But it is neither easy nor attractive.
It would never have been a career choice that many of us would have made.
But now he is a part of my professional life. Only a school could ever bring us together. I console myself that I am serving a greater good.
Our responsibility is to communicate values, to chip away at his anti-social behaviour and attitudes by setting him a different example. The cost to society will be huge if he continues to offend. We put opportunities in front of him in the hope that somehow we can keep him out of prison. But nothing works. Academic, practical, vocational - all have within them authority and rules.
He sees accepting the authority of another as a sign of his own weakness.
The reasons for this must be complex. But his perceptions of what is normal and acceptable are different.
His life is defined by his confrontations. Our professional lives are defined by targets, Would someone like to set me a target as his teacher? To keep him out of prison? To prevent him growing into an abusive partner and father? To stop him crashing into an innocent pedestrian in a car that he has stolen? Because that is his future.
And if these things never happen, no one will ever tell me that I did my job properly.
Ian Roe is a teacher from north Wales