As we continue our circumnavigation of the yard, he points out Ronnie Biggs, who’s sitting on a bench in the far corner surrounded by geraniums.

‘They’ve just planted those, Jeff,’ says Gordon. ‘They must have known you were comin’.’ Again, he doesn’t laugh. I glance across to see a sick old man with a tube coming out of his nose. A man who doesn’t look as if he has long to live.

Another circuit, before I ask Gordon about a young West Indian who has his face turned to the wall, and hasn’t moved an inch since I walked into the yard.

‘He killed his wife and young daughter,’ says Gordon. ‘He’s tried to commit suicide three times since they locked him up, and doesn’t talk to no one.’

I felt strangely compassionate for this double murderer as we pass him for a third time. As we overtake another man who looks totally lost, Gordon whispers, ‘That’s Barry George, who’s just been done for killing Jill Dando.’ I didn’t tell him that Jill was an old friend and we both hail from Weston-super-Mare. For the first time in my life, I keep my counsel. ‘No one in here believes he did it,’ says Gordon, ‘including the screws.’ I still make no comment. However, George’s and my trial ran concurrently at the Old Bailey, and I was surprised by how many senior lawyers and laymen told me they were disturbed by the verdict. ‘I’ll bet he gets off on appeal,’

Once again we are all searched before leaving the yard, which puzzles me; if we didn’t have anything on us when we came in, how could we have acquired anything while we were walking around the yard? I feel sure there is a simple explanation. I ask Gordon.

‘They’ve got to go through the whole procedure every time,’ Gordon explains as we climb back up the steps. ‘It’s the regulations.’

When we reach the third floor, we go our separate ways.