‘I had a drink with him a couple of years ago,’ Batchelor said. ‘In the bar at Brighton nick, when he was Commander of Brighton and Hove. We were talking about what coppers earned. He told me he was on seventy-three thousand pounds a year, plus a couple of grand more in allowances. That might sound a lot, he said, but it is less than a school headmaster earns – and I’m in charge of the entire city of Brighton and Hove. He then said something I’ll never forget.’

She looked at him inquisitively.

‘He said, In this job, the riches come from within.’

‘That’s nice.’

‘And true. Being a copper, doing this job, makes me feel like a millionaire, every day of my life. I never wanted to be anything else.’

They climbed out of the car and rang the doorbell.

Moments later the huge oak front door was opened by a slight, unassuming-looking man of about seventy. He had a trim figure, a kindly, bird-like face, with a small, crooked nose and alert, wide blue eyes filled with curiosity. His thinning head of hair was grey, going on white, and tidy, and he was dressed in a beige cardigan over a gingham shirt, with a paisley cravat around his neck, rust-coloured corduroy trousers, which looked like they were used for gardening, and black leather slippers. The only hint from his appearance that he was a rich man was the faint, but distinct, glow of a tan.

‘Hello,’ he said in a cheery, cut-glass voice that belonged in a 1950s film.

‘Sir Roger Sirius?’ Batchelor asked.

‘That’s me.’ He held out a slender, hairy hand, with long, immaculately manicured fingers.

The detectives shook hands with him, then Batchelor pulled out his warrant card and held it up. Sirius gave it only the most cursory of glances and stepped aside with a theatrical wave of his hand.

‘So, do come in. I’m intrigued to know how I can be of help. Always fascinated by you chaps. Read a lot of crime novels. I quite like The Bill. Ever watch it?’

Both officers shook their heads.

‘Morse. Used to like him. Didn’t care too much for that John Hannah in Rebus, but thought Stott was a lot better. D’you watch them?’

‘Don’t get a lot of time, sir,’ Batchelor said.

They followed the distinguished transplant surgeon across a grand oak-panelled hall. It was filled with antique furniture, as well as several gleaming suits of armour. On the walls was a mix of antique swords, firearms and oil paintings, some of which were portraits, some landscapes.

Then they entered a magnificent study. The walls in here were panelled in oak, too, and hung with certificates evidencing the surgeon’s qualifications. All around were framed photographs of him with numerous famous faces. One was Sirius with the Queen. In another, at a black-tie function, he was with Princess Diana. Others showed him with Sir Richard Branson, Bill Clinton, François Mitterrand and the footballer George Best. Batchelor peered at that photograph with particular interest – Best, famously, had had a private liver transplant.

The two police detectives sat on a studded red leather sofa, while a raven-haired beauty, whom Sirius introduced as his wife, brought them coffee. Sirius was briefly distracted by his BlackBerry buzzing, and Batchelor and E-J used the opportunity to exchange a brief glance. The surgeon was clearly a complex character. Modest in appearance and manner, but not in ego – nor in his taste in women.

‘So, how can I help you?’ Sirius asked, after his wife had left the room, settling down into an armchair opposite them, across the oak chest that served as a coffee table.

Guy had already rehearsed this with E-J on the way over. Suddenly he was feeling badly in need of a cigarette but knew, from the fresh smell of the room and the total absence of ashtrays, that he had no chance. He would have to sneak one later, something he had become used to these days.

Watching the surgeon’s eyes carefully, he said, ‘This is a very beautiful house, Sir Roger. How long have you lived here?’

The surgeon reflected for a moment. ‘Twenty-seven years. It was a wreck when I bought it. My first wife never liked it. My daughter loved it here.’ His eyes went misty, suddenly. ‘It’s just a shame that Katie was never able to see it finished.’

‘I’m sorry,’ E-J said.

The surgeon shrugged. ‘A long time ago, now.’

‘You’ve been quoted many times in the press over your views on the UK organ donor system,’ Guy Batchelor went on, still watching his face intently.

‘Yes,’ he agreed, nodding vigorously, instantly animated by the subject. ‘Absolutely!’

‘We thought that you might be able to help us.’

‘I’ll do my best.’ He leaned towards them and, looking even more bird-like, smiled eagerly.

‘Well,’ Emma-Jane cut in almost on cue, ‘it’s true, isn’t it, that around 30 per cent of patients in the UK who are waiting for a liver transplant will die before they get one?’

‘Where did you get that figure from?’ he asked with a frown.

‘I’m quoting you, Sir Roger. That was what you wrote in an article in the Lancet in 1998.’

Frowning again, he said defensively, ‘I write a lot of stuff. Can’t remember it all. Particularly not at my age! Last I heard, the official figure is 19 per cent – but, as with everything, that depends on your criteria.’ He leaned forward and picked up a silver milk jug. ‘Either of you take milk?’

‘Can’t remember it all. Particularly not at my age.’ But you still hold a private helicopter licence, so your memory can’t be that crap, Guy Batchelor thought to himself.

When he had sorted their coffees out, the DC asked, ‘Do you remember the article you wrote for Nature, criticizing the UK organ donor system, Sir Roger?’

He shrugged. ‘As I said, I’ve written a lot of articles.’

‘You’ve also worked in a lot of places, haven’t you, Sir Roger?’ she pressed. ‘Including Colombia and Romania.’

‘Gosh!’ he said, with what looked like genuine excitement. ‘You chaps have certainly boned up on me!’

Batchelor handed the three e-fit photographs of the dead teenagers across to the surgeon.

‘Could you tell us if you’ve ever seen any of these three people, sir?’

Sirius studied each of them for some moments, while Batchelor watched him, intently. He shook his head and handed them back.

‘No, never,’ he said.

Batchelor replaced them in the envelope.

‘Is it just coincidence that you chose those two countries to work in? The fact is that they are high on the list of known countries involved in human trafficking for organ transplantation.’

Sirius appeared to think carefully before answering. ‘You’ve both clearly done your homework on me, but I wonder – tell me something. Did your research show up that my darling daughter, Katie, died just over ten years ago, at the age of twenty-three, from liver failure?’

Shocked by this revelation, Batchelor turned to E-J. She looked equally taken by surprise.

‘No,’ he said. ‘I’m sorry – sorry to hear that. No, we didn’t know that.’

Sirius nodded, looking sad and bleak suddenly.

‘No reason why you should. She was one of those 30 per cent, I’m afraid. You see, even I couldn’t get around the donor system we have here in this country. Our laws are extremely rigid.’

‘We are here, Sir Roger,’ Emma-Jane said, ‘because we have reason to believe some members of the medical profession are flouting those laws in order to provide organs for people in need.’

‘And you think I may be able to help you to name them?’

‘That’s what we are hoping,’ she said.

He gave a wan smile. ‘Every few months you read on the Internet about some chap or other who gets drunk in a bar in Moscow and wakes up minus a kidney. These are all urban myths. Every organ supplied for donor surgery in the UK is governed by UK Transplant. No hospital in the UK could obtain an organ and transplant it outside this system. It’s a complete impossibility.’