I'm so stressed by the way I've been treated," the prisoner began, "that I've started smoking heroin again."
I asked him politely where he was getting it. "It's everywhere," he replied. "I handed over toiletries I bought from the canteen [prisoners can order from an in-prison shop] and he gave it to me. I know I'm getting addicted. My drug of choice on the outside was crack cocaine. I'd never done heroin until I came in here. I started taking it when I found that my personal papers had been given to the wrong person. It's the prison's fault and an abuse of my human rights."
He added, inevitably, "I want compensation". He'll probably get it.
His situation is not an isolated one. In my regular working trips to and from a B-category London prison, I see how inefficiency, supplies of class A drugs and prisoners who know how to play the system are an intrinsic part of prison life today.
Hardly anyone - apart from staff and criminals - knows what really goes on inside a prison. Because of the obvious security demands, you can get inside only if you are invited. No wonder it's a fascinating, mysterious and sometimes frightening place.
I first became involved with prison life about three years ago and, despite my preparation, I initially felt shocked to be on the wrong side of huge bars and iron gates. It made me understand how losing your freedom is debilitating to the point of impotence. Not being easily able to find out the simplest things, for example your release date, plus having nothing to do seems the ultimate endurance test. But then I am not a criminal.