It was the hottest day of the month so far, although there were still five more days of July remaining. But the forecast suggested that August would be no cooler.

I was sitting in my office above Belgravia police station in central London, with a cup of fresh coffee in front of me and beside it a completed report for the Crown Prosecution Service. My in-tray was empty and the commander had taken the day off. My jacket was hanging over the back of my chair, and I was contemplating the possibility of actually having a weekend off to do exactly as I pleased. And that was to do nothing. What could be better than that?

Unfortunately what we anticipate rarely occurs, and it is particularly foolish for a detective chief inspector who is attached to the Homicide and Major Crime Command of the Metropolitan Police to think such things. Especially at half past two on a Friday afternoon.

'Excuse me, sir.' Detective Sergeant Colin Wilberforce, the incident-room manager, appeared in my office doorway. Colin is a mild sort of guy who's happily married to Sonia, has three children and lives in Orpington. But this gentle giant becomes a ferocious rugby player when he turns out for the Metropolitan Police and has a cauliflower ear to prove his on-field aggressive qualities.

'What is it, Colin?' I was disconcerted by the expression on Wilberforce's craggy face. It had a certain triumphant look about it, and I imagined it was the sort of triumphant look that appears on his face when he's barged his way through the opposing players and is in sight of a touchdown.

'We've got one, sir, and Mr Dean has given it to you.'

'By which I take it that, in his infinite wisdom, Mr Dean has decided to ruin my weekend.' But I couldn't really complain, Patrick Dean was the detective superintendent in charge of our bit of HMCC and his allocation of cases was always scrupulously fair.

'Yes, sir,' said Wilberforce, his face not betraying the slightest amusement, even though I knew that inside he was laughing like a drain. It was all right for him: he had the weekend off.

'What's the SP?' I asked wearily, as I stood up and put on my jacket. Short for starting price, SP is a bit of terminology the police have lifted from the sport of kings, but to CID officers it's a desire to know what's happened so far.

Wilberforce glanced at some sort of electronic gismo he was holding in his hand. 'The body of a deceased male was found in Apartment E, Cockcroft Lodge, Cockcroft Grove, North Sheen, sir. First officers on the scene were told that it was the deceased's home address.' After grinning owlishly, he added, 'It would appear that he'd been shot, sir.'

'Has he been identified?'

'Sort of. His name's Richard Cooper according to the man who called the police.'

'And who was that?

'A man by the name of Dennis Jones who claims to be a friend of Cooper. He's been detained at the apartment pending interview.'

'When did this drama unfold, Colin?'

Wilberforce glanced at his gadget again. 'It was approximately thirteen thirty hours when Jones found the body, sir.' And anticipating my next question, he added, 'Dave Poole is in the car park ready and waiting, and Miss Ebdon is assembling the rest of the team.'

Detective Sergeant Dave Poole is my black bag carrier. And to clear up any ambiguity, it is Dave who is black not the bag. In point of fact there isn't a bag any more, but the term has stuck. Of Caribbean descent, his grandfather arrived in the 1950s and set up practice as a medical doctor in Bethnal Green; his father is a chartered accountant, but Dave, after obtaining a good English degree at London University, claims that in a moment of insanity he joined the Metropolitan Police until he could find a proper job. And I can honestly say that he's the best assistant I've ever had working with me. What I forget, he remembers.

Adopting a mock West Indian sing-song accent in place of his native cockney, Dave frequently refers to himself as the black sheep of the family, thus alarming the more sensitive of those among our hierarchy who consider racial diversity to be far more important than fighting crime. But there's not a lot they can do about Dave making racist remarks about himself, especially when doing so he adopts a sort of downtrodden expression.

I made my way to the car park, where Dave was waiting with the engine running.

The distance to North Sheen from Belgravia is about ten miles, but given that London is probably the most congested city in Europe, Dave did well to get us there in slightly less than forty-five minutes, by dint of what he calls positive motoring.

One glance at the exterior of Cockcroft Lodge was enough to confirm that it comprised a series of upmarket apartment blocks. Looking at the pristine lawns and delicately playing fountains in the gardens, I guessed that my salary wouldn't even cover the maintenance. And that was before I discovered that underground there existed a swimming pool, a gymnasium and a squash court and that there were tennis courts in the gardens at the rear. All of which pointed to the residents being seriously rich people.

A youthful inspector, clutching a clipboard and looking terribly important, stood in the main entrance to the nearest of the three apartment blocks. He raised his pen and opened his mouth as I approached, but I answered the question I knew he was going to ask before he'd uttered a word.

'DCI Harry Brock, HMCC.'

'Thank you, sir,' said the inspector, and waggled his pen at Dave with an officious sort of flourish.

'Colour Sergeant Poole, ditto, sah!' Dave, having guessed that the inspector was one of the aforementioned diversity worriers, adopted his West Indian sing-song accent and contrived to look like a recently emancipated slave.

The inspector gulped and scribbled on his clipboard. So far he had remained silent, but as he probably hadn't anything useful to contribute that was undoubtedly for the best.

A uniformed constable whose ravaged and weary seen-it-all face gave him the appearance of one old enough to be the inspector's father smirked and lifted the blue-and-white tape. 'First floor, guv. The hat inspector's there.'

The HAT inspector is so called not because of a propensity for eccentric headgear or, for that matter, any sort of headgear. The acronym HAT means Homicide Assessment Team, a roving band of detective inspectors, male and female, who are called upon to determine if a suspicious death is a homicide. And if it is, that's where I come in. There was a time when the Murder Squad at Scotland Yard was so small that its members knew each other, but now there are over seven hundred of us. Nevertheless, we're told by the inhabitants of that self-deluding dream factory known as the Home Office that incidents of major crime are on the decline.

Dave and I took the stairs to the first floor. I have a negative attitude towards lifts; they tend to malfunction when you're in a hurry, and it's embarrassing if you get stuck in a lift when you're on your way to investigate a murder. It happened to me some years ago, but I can still recall the collective sniggering of the firefighters who eventually liberated me.

'Afternoon, guv.'

'Still not doing me any favours, then, Jack.' I had first met Jack Noble, the HAT inspector, at the scene of a murder one snowy February morning in Chelsea.

'Sorry about that, guv'nor. People will go about getting topped, but at least the weather's better. To get down to business, Dennis Jones, the guy who found Cooper's body, is inside. He'll tell you the tale, and it all sounds pretty sussy.'

'How so?' I asked.

'He struck me as being a bit iffy, and he's a wimp. I didn't question him, of course, but what he told us when we arrived didn't seem to ring true.' Noble shrugged. 'You might take a different view, though.'

'Thanks for the heads-up, anyway, Jack.' Most CID officers will tell you that the view of the first detective on the scene is invaluable.

There was little doubt that Richard Cooper's apartment was expensive, but it was not to my taste. It was what I think the chattering classes call minimalist, which is another way of saying you don't have much furniture and excuse its absence by pretending that it's very much the trendy way to live.

Or in Richard Cooper's case, die.

The body was sprawled face up, arms outstretched, on the floor of the living area. I deliberately didn't use the term 'living room' because there was no easy way of working out where the various functions began and ended. Imagine a sitting area with a large uncomfortable sofa, a dining area with a glass-topped table and uncomfortable chairs, and a sort of kitchenette arrangement. All merged into one huge space that seemed, at first glance, to be about half an acre. And large picture windows affording panoramic views of ... well, Hounslow. Pollution permitting.

My first impression of Richard Cooper was that he was about thirty-two years old, but I later learned that he was thirty-five. And he was prematurely bald. He was dressed in light-blue linen trousers, Gucci suede loafers and a white silk shirt. At least, it had been white when he put it on, but there was now a large bloodstain across the front and several holes in the material near the location of the heart.

'That's no way to treat an expensive shirt,' observed Dave.

'Where's this Dennis Jones now, Jack?' I asked, seeing that he wasn't in the living area.

'I've put him in one of the bedrooms,' said Noble. 'Mrs Maxwell – she lives in Apartment F opposite – offered to look after him until you arrived, but she could be a material witness so I've kept them apart. Jones has obviously had a touch of the vapours, but the first officers on the scene said he refused medical assistance.'

'You say that this Maxwell woman could be a material witness?'

'Yeah. When police arrived, she was standing outside her front door and volunteered the information that she'd heard two or three loud bangs at around one o'clock.'

'Don't tell me, she thought it was a car backfiring.'

'No,' said Noble with a laugh. 'Strange to relate, she thought they were gunshots. Being a hot day, most people have got their windows open – there are another two apartment blocks behind this one – and she couldn't make out where the noise had come from. She eventually put it down to someone watching an American cop show on television. Then, about half an hour later, this Jones guy banged on her door and asked her to call the police and an ambulance, which she did, and suddenly there were coppers running about all over the place. Her words, not mine,' he added, smiling. 'The skipper on the Q car, who was first officer on the scene, straight away sussed out that it was a murder and called me.'

'I'll have a word with Jones while we wait for the cavalry to arrive. Who's the pathologist?'

'Doctor Mortlock. He was complaining that he had to come from Chelsea, but he should be here any minute. I suppose he's dealing with another dead body.' Noble sighed. 'Never rains but it pours,' he said.

'Chelsea's where Dr Mortlock lives, and he's always complaining about something.' I shook hands with Noble. 'Thanks, Jack.'

'Be lucky, guv,' said Noble, and went on his way.

The rest of the supporting cast arrived together. Detective Inspector Kate Ebdon headed the team of detectives that always worked with me; and Linda Mitchell, the crime-scene manager, was accompanied by a band of murder technicians bearing the tools of their trade. DI Len Driscoll would be back at the incident room, ready to deal with anything that needed a bit of weight.

'I'll leave you to oversee the scene, Kate, and the usual local enquiries; you know the form,' I said, 'while Dave and I interview the guy who found the body. But leave Mrs Maxwell in Apartment F opposite. I'll speak to her.'

I left Kate to organize her officers into doing what was necessary in a murder investigation, such as starting house-to-house enquiries. Or in this case, apartment-to-apartment.

The bedroom was large and was dominated by a huge bed. I knew about king-size beds, super-king-size beds and even emperor-size beds, but this one was even larger. One wall was covered with mirrored sliding doors, behind which, doubtless, was a wardrobe full of expensive suits, shirts and ties. Assuming he was someone who wore a tie. There aren't many of us left.

I glanced at the man slumped in one of two armchairs, both of which were skeletal in design and looked as though they were only half finished.

'Dennis Jones?'

'Yes, that's me.' Jones struggled to stand up, but I waved him down.

By the look of him Jones was probably around thirty years of age. He had large owl-like spectacles through which he blinked repeatedly. His pale face may have been the natural complexion of someone who spent his whole life indoors, or it may be that he was still in shock. Nevertheless, it was a face that betrayed an overall weakness of character. He was curiously dressed, at least by my standards: a pair of the ubiquitous blue jeans and a dark-blue shirt, the collar, cuffs and patch pocket of which were pale blue. This bizarre ensemble was completed by a pair of light-blue shoes with thick white-rubber soles. I imagined this to be his idea of what the modern man-about-town should wear.

'I'm Detective Chief Inspector Harry Brock, Mr Jones, and this is Detective Sergeant Poole. Just relax and tell me what you know about this business.'

'You wouldn't happen to have a cigarette, would you? I've been trying to give up, so I haven't got any with me.'

'I'm afraid you'll have to wait until you're out of here,' said Dave. 'This whole area is a crime scene and we don't want it contaminated.'

'Oh, I see. I didn't understand that.' Jones's hands were shaking so much that he eventually pushed them into the pockets of his jeans. 'It's the first time I've ever seen a dead body.'

'I guessed that,' I said, but didn't feel a great deal of sympathy. One of the regrettable facts of life – or should that be death? – is that coppers very quickly become inured to the sight of what man can do to his fellow man. 'I understand that it was you who found Mr Cooper.'

'Yes.'

'Why did you call on him?' asked Dave.

'He asked me to.'

'Why did he ask you to call on him?' Dave was being extremely patient, but he knew that a nervous witness was unlikely to respond if an investigating officer pushed him too hard.

'He was scared.' Jones flicked his long blond hair out of his eyes. It was a habit that was to be repeated frequently during the course of our conversation.

'What was he scared of?' I'd been tempted to say that he apparently had good reason, but this wasn't the time for flippant remarks.

Jones looked nervously in my direction and began to blink through his glasses again. 'All he told me was that someone had threatened to kill him. In fact, he'd taken the threat so seriously that he'd moved out of his apartment and was staying in a hotel.'

'D'you know the name of the hotel?' I asked.

'No. He said it was better I didn't know.'

'What was he doing back here, then?' Dave glanced up, a suspicious expression on his face.

'He'd come back to get a change of clothes and to pick up some papers connected with his work.'

'How d'you know that's why he was coming back?'

'Because he rang me and asked me to meet him here. He didn't want to be here on his own in case this person turned up.'

'What time did he ask you to meet him?' I asked.

'At about one o'clock.'

'And when did you get here?'

'About half past one, I suppose it must've been. There was an accident on the M4 and I got held up.' Jones shook his head. 'If I'd been here, this wouldn't have happened.'

'If you had been here, you'd probably have been shot as well,' commented Dave cynically. 'What d'you know about this person who was threatening Mr Cooper?'

'Nothing,' Jones said. 'Dick wouldn't tell me. He said that if I knew, it would put me in danger as well.'

'You said he'd come back for a change of clothing and to pick up some papers connected with his work,' said Dave. 'What was his job?'

'I don't know,' said Jones. 'But if this flat is anything to go by, it pays well.'

'I think that'll be all for the moment, Mr Jones,' I said, 'but we'll need to speak to you again before you leave. In the meantime, perhaps you'd give your details to my sergeant here.'