There was a time when Nick Miller had aspired to a black belt in karate or judo, but the pressure of work had interfered with that pursuit as it had with so many things. When he entered the premises of the Kardon Judo Centre on the following morning, it was his first visit in a month.

Bert King, the senior instructor, was dressed for the mat, but sat at his desk reading the morning paper, a cup of coffee in his hand. He was a small, shrunken man whose head seemed too big for his body and yet in the dojo, he was poetry in motion, a third dan in both judo and aikido.

‘Hello, Mr Miller, long time no see,’ he said cheerfully.

‘I don’t seem to have time to turn round these days,’ Miller said, ‘but I’ve got an hour to spare this morning. Any chance of a private lesson?’

Bert shook his head. ‘Sorry, I’ve got a client in the dojo now warming up. I was just going to go in.’

‘Anyone I know?’

‘I don’t think so, he isn’t one of the regulars. A chap called Craig.’

Miller paused in the act of lighting a cigarette. ‘Colonel Duncan Craig?’

‘That’s right. Do you know him?’

‘We’ve met. Is he any good?’

‘You’re telling me he is,’ Bert King said emphatically. ‘His aikido is murder – brown belt standard at least. Maybe even first dan and the strange thing is, he isn’t even graded. He’s been coming in two hours each day for a fortnight now and it’s taking me all my time to hold him, I can tell you.’

‘Mind if I watch?’

‘Help yourself.’ He moved out of the office, opened the door to the dojo and went inside. Miller hesitated for a moment and then followed him.

Craig and King faced each other in the centre of the mat. The Colonel was wearing an old judogi and looked fit and active, vibrant with energy like an unexploded time bomb.

‘Free practice?’ Bert King said.

Craig nodded. ‘All right by me.’

The contest which followed lasted just under fifteen minutes and was one of the finest Miller had seen. When it finished, both men were damp with sweat and Bert King looked shaken for the first time since Miller had known him.

‘I must be getting old,’ he said. ‘Ten minutes’ rest and then we’ll brush up on some of the finer points.’

‘That’s fine by me.’ Craig picked up his towel from the bench to wipe the sweat from his face and noticed Miller in the doorway. ‘Hello, Sergeant, we seem to be running into each other all over the place.’

‘We’ll have to get Sergeant Miller on the mat with you one of these days,’ Bert said.

Miller shook his head. ‘No thanks. He’s too rich for my blood.’