"Yeah, I see." He showed Stephanie a sardonic grin. "I still say you'll have trouble convincing people to let them out again."

She shrugged.

"Have you actually tried implanting any of these alternative memories in an inmate?" he asked.

"Indeed we have," MacLennan said. "Nothing dramatic. It's early days yet. We are in the process of acquiring baseline data on how well the paradigms are absorbed." He might have been talking about lab rats for all the emotion in his tone. "The older the subject, the more difficult it becomes, naturally."

"What about Liam Bursken? Has he been given any synthetic memories?"

"No. He was unwilling to co-operate. At the moment it remains a purely voluntary programme, although we do reward participants with extra privileges."

"So essentially he is the same person now as he was when he arrived."

"Yes."

"Great." Greg stood up. "I'd like to see him. He should be able to offer me a few insights."

"As you wish," MacLennan said. "Stephanie will take you down."

"Do you have records of the correspondence he's received?" Greg asked.

MacLennan glanced enquiringly at Stephanie.

"Yes," she said. "It's not much, mostly death threats."

"I'd like copies, please."

"I'll assemble a data package," MacLennan said. "It'll be ready for you when you leave."

"Thanks." There was always the possibility someone had admired Bursken enough to copy the murder technique. Pretty tenuous, though.

"How has Bursken reacted to the Kitchener murder?" Greg asked Stephanie when they had left MacLennan's office.

"He's shown a lot of interest," she said. "He believes it is a vindication of his own crimes."

"Oh?"

"According to Bursken, he is one of God's chosen agents of vengeance in a sinful world. Therefore someone murdering in the same way is proof that God is now instructing them. Therefore, God was instructing him in the first place. QED."

"What's he like? I mean, what sort of formative years did he have that could push him into that?"

She hesitated as they walked into the stairwell, her companionability glitched momentarily. Greg was actually allowed to see worry and even confusion.

"The honest truth, Greg, is I haven't got a clue. We did some research into his background, for all the good it did us. He had a perfectly ordinary childhood. There was some bullying at school, nothing excessive. We could find no evidence of any sexual or mental abuse, no deprivation. Yet even by the standards of this Centre's inmates, he is completely insane. There is no rational explanation for why he went haywire. We have studied him, naturally; his brain function shows no abnormality, there are no chemical imbalances.

"Currently we're trying to determine the actual trigger mechanism of his psychosis, whether there is a single cause to send him off on his killing sprees. MacLennan thought that if we could just gain one insight into how Bursken functions we might eventually be able to understand his mentality. That's why he's prepared to devote time and money on such a hopeless case. By studying the real deviants, we gain more knowledge of the ordinary. But the results have been very patchy, and completely inconclusive. I doubt we ever will understand. I simply thank God that Bursken is a rogue, very rare."

"You mean, even your laser paradigm couldn't cure him?"

"I shouldn't think so. You see, as far as we can tell, there is no evil memory sequence to replace, no trauma to eradicate. Maybe he did hear voices, who knows?"

The Centre's interview room was slightly more hospitable than the one at Oakham police station. Greg imagined it had been patterned from a conference room at a two-star hotel, cheap but well meaning. The table was a cream-coloured oval with five comfortable sandy-red chairs around it, almost like a dining room arrangement; certainly the confrontational element was absent. It was on the ground floor and a picture window ran the length of one wall, looking out on the patio garden which filled the building's central well. Conifers and heathers were growing in raised brick borders, tended by a working party of inmates under the watchful eyes of warders; there were several wooden park benches with inmates sitting and reading, or just soaking up the unexpected bonus of sunlight. They all had a blue stripe on their uniform sleeve.

Two guards brought Liam Bursken in. He wasn't a particularly tall man, five or six centimetres shorter than Greg, but powerfully built, with broad sloping shoulders; his shaved skull had a slightly bluish sheen from the stubble, giving the impression of a long gaunt face. The neural jammer collar was tight enough to pinch his skin, Greg could see it was rubbing red around the edges. Sober, almost mournful, emerald eyes found Greg, and regarded him intently. There was a red stripe on his yellow uniform sleeve.

He sat down slowly, his joints moving with the kind of stiffness Greg associated with the elderly. The guards remained standing behind him, one with his hand in his pocket. Fingering the collar activator, Greg guessed.

He ordered a secretion from his gland. The four minds in the room slithered across his expanding perception boundary, their thought currents forming a constellation of surreal moire-patterns. Both guards were nervous, while Stephanie Rowe by contrast displayed a cool detached interest. Liam Bursken's thoughts were more enigmatic. Greg had been expecting the ragged fractures of dysfunction, like a junkie who simply cannot rationalize, but instead there was only calmness, a conviction of supreme righteousness. Bursken's self-assurance touched on megalomania. And there was no sense of humour. None. Bursken had been robbed of that most basic human trait. It was what unnerved people about him, Greg realized, they could all sense it at a subconscious level. He wondered if he should tell Stephanie, help her understand the man.

He put his cybofax on the table, and keyed in the file of questions he'd prepared. "My name is Greg Mandel."

"Psychic," Liam Bursken said. "Ex of the Mindstar Brigade. Adviser to Oakham CID in the murder of Edward Kitchener. Strongly suspected to have been appointed at the insistence of Julia Evans."

"Yeah, that's right. Though you can't believe everything you see on the channels. So, Liam, Stephanie here tells me you've been following the Kitchener case with some interest."

"Yes."

Greg realized Bursken was neither being deliberately rude, nor trying to irritate him. Facts, that was all the man was concerned with. There would be no garrulous ingratiation here, none of the usual rapport. Stephanie had been right, Bursken was utterly insane; Greg wasn't entirely sure he could be labelled human.

"I would like to ask you some questions, do you mind?"

"Any objection would be irrelevant. You would simply take your answers."

"Then I'll ask them, shall I?"

There was no response. Greg began to wonder if he could spot a lie in a mind as eerily distorted as the one facing him.

"How old are you, Liam?"

"Forty-two."

"Where did you live while you carried out your murders?"

"Newark."

"How many people did you kill?"

"Eleven."

Greg let out a tiny breath of relief. Liam Bursken wasn't attempting to evade, giving his answers direct. That meant he would be able to spot any attempts to scramble round for fictitious answers. Even a total mental freak couldn't escape the good old Mandel thumbscrews. He wasn't sure whether to be pleased or not. To comprehend insanity did you have to be a little insane yourself? But then who in his right mind would have a gland implanted in the first place?

He noticed the wave of hatred washing through Bursken's mind, and clamped down on his errant smile.

"Where were you when Edward Kitchener was killed, Liam?"