Outside Claridge’s, Reynolds counted the Christmas trees mounted on the canopy over the door. Five. But they were all quite small. The principal tree was in the lobby. It had been placed alongside – and was as high as – the curving white staircase. It seemed to have been steeped in blurred gold. There were also giant bouquets of lilies wrapped in silk bands. A very clean fire burned behind a transparent screen. Orange sparks would occasionally fly upwards like a sort of special effect. Almost all the guests coming through the revolving doors carried branded shopping bags. A woman in what looked like a zebra-skin coat carried a Harrods bag no more than six inches square, like a normal Harrods bag drastically shrunk. But no doubt there was a diamond in there. Most of those who came through the front door went upstairs. Reynolds decided that those coming down the stairs looked like guests on an old-fashioned chat show.

At six-twenty, afternoon tea was still going strong in a mainly green-and-white area behind glass. It had the feeling of a conservatory and the two most perfect blooms were immediately apparent in the form of two young Asians. The young man was drinking tea, the woman a pink concoction – it was perfectly possible that it was pink lemonade. The young man was imperious, crow-like, with a high black quiff. Reynolds could have looked at the woman for hours. In practice, he gave repeated, furtive glances. She was perhaps slightly too thin. She smiled at him and looked down. Demure, that was the word, but women only ever looked demure. It was more of a word than a genuine quality. The young man was advancing towards Reynolds.

‘Hello sir, I recognise you from the newspaper. I wanted a very quick word. Shall we go this way?’ He indicated one of the hotel bars, which was behind glass doors to one side. It seemed they would be leaving the woman behind, which was a shame. Perhaps she not only did not drink alcohol, but also couldn’t bear to be near it. Rakesh Dutta bent low and whispered something in her ear, and she nodded, smiling.

The bar had that expensive, controlled darkness that only the top hotels can manage. Reynolds heard an English voice: ‘For a serious lunch it simply has to be Gavroche’; then an Arab-sounding voice: ‘You would fit right in and the money is very likeable.’

‘How are you?’ asked Rakesh Dutta.

‘Very well,’ said Reynolds, wondering whether the question had been prompted by the reek of Dettol coming off him. ‘You?’

‘I have had a mediocre trading day, otherwise good. No complaints. This is my treat,’ he added, as they looked at the drinks list.

‘Thanks,’ said Reynolds, ‘I’ll have a glass of white wine.’

He would need to enter it in the Hospitality Register. Tea or coffee could be accepted at any time from anyone. It was all right to accept an alcoholic drink or similar if to refuse would ‘cause offence or damage working relationships’. But the drink must be entered. This could be done by filling in a form, either on paper or via the appropriate intranet portal. Quinn had made no entries by either method since setting up the new unit. Reynolds had checked.

‘Which wine exactly?’ asked Ravi.

‘Just the house.’

‘Can I take the liberty of mentioning the Muscadet? It is particularly good.’

Reynolds had thought Muscadet was a sweet wine, but it turned out not to be. Dutta had a glass of champagne. Reynolds had noted the price of a glass of champagne: thirty pounds. It seemed reasonable to assume that his own wine would also be unreasonably expensive. He would put it down at twelve pounds. When Dutta ordered there seemed to be a note of familiarity in the waiter’s, ‘How are you, sir?’

‘I will come down to it straight away,’ Dutta said. ‘A very good friend of mine, John-Paul Holden was killed, murdered, nearly two months back. That was in Hampstead, yes, but he worked in Mayfair – in the world, you could say, of the super-rich, and hence my call to you. We met as Cambridge undergrads, and we went into the financial world at the same time. John-Paul did very well.

‘He had a first-class degree from Cambridge. I had a first-class degree from Cambridge. These laurels come your way. They are ten a penny in this world. But you need talent for finance just as you need it for football or music or anything else. It is not only a matter of brains. In his first job, in management consultancy, John-Paul was on it, and he was an outperformer. He could see what a business needed, and he could put the people in place to bring that about. I mean he is twenty-two, and he is turning around the turnaround guys, so he gets all the laurels again, and he decides on a new move. He goes to work for a hedge fund. It’s called Rolling River, and it’s run by a very heavy character from the South of America – I mean the American South – name of Eugene Crawford. He is formidable, you could say, but he has a very impolite manner, and if you falter with him there will always be repercussions. I have met this guy, and believe me, he does not have a funny bone; a very bad guy to be on the wrong side of.’

He leant closer, speaking more quietly.

‘Eugene Crawford did not rate John-Paul in his new job, and it is true, John-Paul was probably too conservative in his trades. I would say he was a natural long-position guy. It was not the job for him, and he had made the wrong jump.

‘Eugene Crawford begins to marginalise my friend, and believe me, that takes its toll. Under pressure, he makes a mistake, and does a trade that is basically illegal because of inside information. He goes to the compliance officer and puts his hands up but he is told “Forget it, because we can’t afford the scandal.” But before, or after, that I’m not sure, he turns himself in to the regulator. You must know this …’

Reynolds explained that he was not investigating this particular case.

‘Then the investigating people must know it by now, and Eugene Crawford must know it. And, he must have known it before John-Paul was killed.’

‘And you’re saying that’s why he was killed.’

‘Insider trading … If that is found to have occurred that fund is going down; those people are going to be on the streets. I do not say that Eugene himself is a killer, but a man like that has people to do his bidding, and maybe one of them went over the top; like way over.’

Reynolds asked further questions for clarification, and told Dutta he would pass on his name and contact details to the team investigating the killing of John-Paul Holden. This had been a gratifying conversation. Reynolds was glad to be able to do something for Xavier Hussein. This Crawford seemed a legitimate suspect, and Reynolds very much hoped he had killed John-Paul Holden on Hampstead Heath, because then Anna Samarina wouldn’t have.

‘I am fine with that,’ said Rakesh Dutta, and he shook hands with Reynolds before retreating to the glamorous woman in the tea-drinking area. As Reynolds approached the front door, he was nearly knocked over by a man who barked at the doorman, ‘Do you have an umbrella for me?’ But in fact it was not raining. It was a beautiful, blue night with a full moon tracking over the West End. With Christmas only a fortnight away, it was also one of the big party nights of the year, Reynolds thought, watching the Claridge’s doorman despatching and receiving the fast succession of taxis. He himself did not take a taxi, but walked in the direction of the London Library.

When he reached St James’s, he took a detour, towards the stately clubs of Pall Mall, most with golden flares burning outside. He headed east, and turned into the street called Carlton House Terrace. The building of that name – to which almost the entire street was given over – was silent and largely dark. It offered no clue as to why Quinn had written down its name, albeit in abbreviated form. Once, famous aristocrats had lived there. Now it was mainly the offices of money companies. Through basement windows, Reynolds could see dark, bland committee rooms. The street turned a right angle into a square, overlooked by the end of the terrace. There was work going on at this end of it, some sort of refurbishment. Notices read ‘Site Safety Starts Here’ and ‘Construction Sites Are Dangerous’.

St James’s Park lay across the Mall, which was illuminated, Reynolds noticed for the first time, by lights that were oddly white and luminous: gas lights. For the tourist. It was a Royal Park, and so must be kept beautiful, hence no CCTV either in the park or along the Mall; hence the shooting of Quinn. In spite of those tourists the park would be a spot worth thinking of for any bold shootist who knew Quinn’s habits. (Clifford had said he liked to go there alone to read a newspaper and smoke a cigarette.) At the Yard, Reynolds had picked up gossip about Lilley’s investigation. After many hours watching CCTV of cars on Constitution Hill and Trafalgar Square – which was where the CCTV kicked in at either end of the Mall – he still apparently had nothing.

Reynolds turned again to the terrace. If you were going to shoot a man sitting on a bench more or less centrally located in that park with a well-sighted rifle, you might choose the south-facing top-floor rooms of this end. Perhaps the assassin was an engineer with access to the offices of the Royal Academy of Engineering, or a pathologist from the Royal College of Pathologists, because there must be pathological pathologists, and both organisations were accommodated in Carlton House Terrace. But Reynolds had been shot from relatively close range with a pistol. In any case, why would anybody write down the name of a place from which they might be shot?