It all happened 25 years ago, and far away, and yet I carry the memory with me always. It returns to me one way or another every day. Nothing in my professional life has ever had greater importance. For a three-week period an uncontrolled madness enveloped a classroom close to mine.
Mr Peak should never have been in teaching, but someone put him in the school as a favour. It was a tough school and within moments the children had weighed him in the balance and found him wanting. And they turned on him.
The lessons were anarchic. After a couple of days, Mr Peak, realising that he couldn't cope, withdrew into himself. I did what I could. I would tape stories for him to play to the class, since he was unable to read aloud audibly. But he would put on huge padded headphones and listen to them with his back to the collapse of the classroom. Children undressed. Girls revealed themselves. Boys fought. He was abused and bullied.
It was not normal naughtiness, either. It was as if the presence of someone completely unsuitable destroyed all boundaries. Thankfully the chaos rarely spread. The children realised that his classroom was an alternative universe where normal rules no longer applied. Bums were hung out of windows, books were burnt. There was drinking and smoking. I think he had a symbolic importance to his pupils: through him, they could strike back at the system which enslaved them.
In the end the teachers turned against him, too, because he was odd, not a nice person. He felt we were beneath him and had nothing to teach him.
There came a point at which the pupils themselves couldn't go on. They knew what was happening was wrong and they asked for the reintroduction of order. They did not like the forces they had unleashed; they had discovered unpleasant things within themselves. They were like devils, sick of sin. So they approached the head. There were phone calls. Mr Peak was led from the school and went off to join a religious order.
The pupils resumed their normal disaffection and the anarchy that Mr Peak had unwittingly inspired drifted into the school's folk memory. The sorry story has never left me - I learnt more in that short space of time than I ever had before.
You need to want to be a teacher. To be good at it you can't sit down and learn it. You need to possess fundamental qualities. You can't strike disdainful attitudes and believe that you are fundamentally superior to children. They will find you out. They always do. Then you pay the price. That relationship is the key.
A lot of what goes on between pupil and teacher happens at an instinctive level. Children can smell fear - and they respond accordingly. We could smell it, too. We knew Mr Peak was a disaster and nothing could change the fact that something fundamental was missing. He couldn't teach and was never going to be able to do so. How it must have affected him I cannot imagine. Hostility and contempt hung in the air around the poor man.
Things have changed enormously. Perhaps it doesn't happen like this anymore. Perhaps such people are filtered out. But some things do not change. I see now, as clearly as ever, that teachers work best when they work together, that children learn best where they feel safe and confident, that without proper engagement with young people you will never be successful. You have to like children and establish the relationships that make learning possible. Children should be the reason you became a teacher. And it is your responsibility to work with them.
It is all a quarter of a century ago, now. For me it is time to step aside. My work is done. But if I can be indulged one last time, I would like to offer a final piece of advice to teachers everywhere. Enjoy it. And have fun.
Geoff Brookes, former deputy head of Cefn Hengoed Community School, Swansea, is a part-time quality champion.