DAY THIRTY. 7.00 a.m.

It was now three days since the murder, and Coleridge felt as if his investigation had scarcely begun. No forensic evidence of any value had emerged from the search of the house, the suspect interviews had revealed nothing but apparent shock and confusion, the observers at Peeping Tom could not suggest even a hint of a motive, and Coleridge and his excellent team had been reduced to sitting about in front of a television making wild guesses.

Coleridge closed his eyes and breathed slowly. Focus, he had to focus, forget the storm that was raging around him and focus.

He tried to free his mind, rid it of all thoughts and preconceptions, make of it a blank page upon which some invisible hand might write an answer. The murderer is … But no answer came.

It just didn’t seem credible that there had even been a murderer, and yet there had most definitely been a murder.

How could it be possible to get away with murder in an entirely sealed environment, every inch of which was covered by television cameras and microphones?

Eight people had been watching the screens in the monitoring bunker. Another had been even closer, standing behind the two-way mirrors in the camera runs that surrounded the house. Six others had been present in the room left by the killer to pursue his victim. They were still there when he or she returned shortly thereafter, having committed the murder. An estimated 47,000 more had been watching via the live Internet link, which Peeping Tom provided for its more obsessive viewers.

All these people saw the murder happen and yet somehow the killer had outwitted them all.

Coleridge felt fear rising in his stomach. Fear that his long and moderately distinguished career was about to end in a spectacular failure. A world-famous failure, for this was now the most notorious case on the planet. Everybody had a theory – every pub, office, and school, every noodle bar in downtown Tokyo, every Turkish bath in Istanbul. Hour by hour Coleridge’s office was bombarded with thousands of emails explaining who the killer was and why he or she had done it. Criminologists and Crackers were popping up all over the place – on the news, in the papers, on-line and in every language. The bookies were taking bets, the spiritualists were chatting to the victim and the Internet was about to collapse under the weight of traffic of webheads exchanging theories.

Indeed, the only person who seemed to have absolutely no idea whatsoever of the killer’s identity was Inspector Stanley Spencer Coleridge, the police officer in charge of the investigation.

He walked through the house, trying to gain some sense of its secrets. Asking it to give him some clue. Not the real house, of course. The police forensics team had completed their business there in a day and had then been obliged to return it to its owners. This was a replica house that Peeping Tom Productions had been happy to lend to the police. The plasterboard and glue version that the producers had used during the months of camera rehearsal, during which they had ensured that every single angle was covered and that there truly was no place to hide. This replica house had no roof or plumbing and did not include the garden, but internally its colours and dimensions were precise. It gave Coleridge the feel.

He cursed himself. Standing in the imitation space, he felt that he had become like one of the actual housemates: he had no useful thoughts in his head whatsoever, only feelings.

“Feelings,” Coleridge thought. “The modus operandi of an entire generation. You don’t have to think anything, or even to believe anything. You only have to feel.”

Like the real house, the replica house, which stood on an empty sound stage at Shepperton Film Studios, consisted of two bedrooms, a shower room, a bathroom in which laundry could be done in a big steel trough, a toilet, an open-plan living, kitchen and dining area, a store room, and the room known as the confession box, where the inmates went to speak to Peeping Tom.

Three dark corridors ran along the edges of the house that did not open out onto the garden, and it was along these corridors that the manned cameras travelled, spying on the inmates through the huge two-way mirrors that took up most of the walls. These cameras, combined with the remote-controlled “hot-head” ones situated inside the house, ensured that there was not a single square centimetre of space in which a person might avoid being observed. The only room that was not covered by the manual camera runs was the toilet. Even Peeping Tom’s obsessive voyeurism had drawn a line at having cameramen standing eighteen inches from the inmates while they evacuated their bowels. The duty editors had to watch, however, as the toilet contained a hot-head, which missed absolutely nothing. They had to listen, too, as the cubicle was also wired for sound.

Coleridge was reminded of the catchphrase that had adorned so many roadside posters in the run-up to broadcast, “THERE IS NO ESCAPE” they had read. For one of the inmates that statement had proved horribly prophetic.

The house and garden complex was surrounded by a moat and twin lines of razorwire fencing patrolled by security guards. The monitoring bunker in which the production team worked was situated fifty metres beyond the fence and was connected to the camera runs via a tunnel under the moat. It was along this tunnel that Geraldine and the horrified Peeping Tom night crew had run on that dreadful night after they had witnessed a murder on their television monitors.

The murder.

It was eating Coleridge up.

For the umpteenth time he walked across the replica of the floor that the victim had crossed, to be followed moments later by the killer. Then he went and stood in the camera run, looking in on the room, just as the operator had done on the fatal night. He re-entered the living space and opened a drawer in the kitchen unit, the top one, the one the killer had opened. There were no knives in the drawer Coleridge opened; it was only a rehearsal space.

Coleridge spent almost three hours wandering around the strange, depressing replica, but it told him nothing more about what had happened during the few, brief moments of dreadful violence than he already knew. He asked himself how he would have carried out the murder had he been the killer. The answer was, in exactly the same way as the killer. It was the only way it could have been done with any chance of getting away with it. The killer had seen his or her one opportunity to kill with anonymity and had seized it.

Well, that was something, Coleridge told himself. The speed with which the killer had grasped his or her chance surely proved that he had been waiting and watching. He or she had wanted to kill.

What could possibly have happened to engender such hatred? Without any evidence to the contrary, Coleridge had to presume that these people had all been complete strangers to each other less than a month before. He and his team had been studying the background of all the housemates but had so far found not one shred of a suggestion that any of them had known each other prior to entering the house.

So why would a stranger plan to kill a stranger?

Because they were strangers no more. Something must have happened or been said in those three weeks that had made murder inevitable. But what? There had certainly been some dreadful goings-on in the house, but nothing had been observed that looked remotely like a motive for the crime.

It could not be ruled out that two of the inmates had not been strangers. That some ancient enmity had been unwittingly introduced into the house? That some bleak and terrible coincidence in the selection process had led to murder?