"I can't," said Malika, as she took back her comb.

Moz poured away the saucer of lemon juice in silence.

"And I won't," she added.

"Then I will," said Moz. "And I'll do it by myself."

Their fight was about whether Malika would help him deliver a package of drugs for Caid Hammou and about the fact that Moz wanted to get his hands into Malika's pants and Malika wasn't entirely sure she'd let him.

The year was 1977.

Wreckless Eric had signed to Stiff, Television's LP Marquee Moon was ripping apart the souls of all who heard it, Sheena was a punk rocker. The Sex Pistols, about the only good thing to come out of the jubilee of Queen Elizabeth II, had got to number one in the UK charts and been banned from Woolworth's. Neil Young was two years away from the greatness that was Rust Never Sleeps.

Despite their clothes, Malika's attempts to bleach her hair and the shades hiding the tears which now hung in the corner of Moz's eyes, none of the above names meant a thing to either of them.

Charlie Bilberg's brief was simple: extract the maximum amount of information with the minimum amount of Amnesty International outrage and clear the Marrakchi case off his section chief's desk before the end of the third week in July.

Charlie's section chief had not specifically tied this end date to the beginning of Ramadan, that month when all devout Moslems fast during the hours of daylight, but the young agent was bright enough to make the connection for himself. There was no point igniting an already flammable situation.

A military court had been convened and the fact that Colonel Borgenicht had yet to hear any evidence was not enough to stop Fox News and a number of the tabloids reaching their verdict in advance. The only thing seemingly still open for discussion was how the execution should be carried out.

Agent Bilberg was there to sift advance evidence.

Actually he wasn't there at all. He would be arriving in Marrakech next week and staying at a flat in Gueliz arranged by the US consul on behalf of the American ambassador.

This week he was on leave, that was what it said on all official records. Which was how Charlie Bilberg found himself sleeping at a Hivernage tourist hotel in the New Town, surrounded by package-tour Austrians who descended on the morning buffet and cleared it of cheese, sausage and sliced meat before Charlie had finished his first cup of coffee.

He'd been careful to do holiday things, spending two mornings at a café just off Djemaa el Fna, drinking mint tea at a plastic table, while hard dance from a tiny machine shop opposite competed with the café's choice of soft rock, which often switched between French, English and Arab, mostly in the same song.

And both times he'd paid for his mint tea with a twenty-dirham note, one black with grease and smelling of ginger and cinnamon from the thousands of previous owners who'd eaten only with three fingers and their thumb.

As night fell he'd wandered the oily smoke of Djemaa el Fna's famous barbeques and watched belly dancers, covered from head to toe in thick white dresses which were sewn with golden chains that perfectly accentuated the fullness of their breasts and the divide of their buttocks.

A man in a loose jellaba had grabbed his own balls and jiggled them up and down in Charlie Bilberg's direction as Charlie turned away from the belly dancers, and he still didn't know if this was a deadly insult or an offer to come back to his hotel in Hivernage.

And in between all this, Agent Bilberg had sat at a desk in his first-floor room and listened to the recording of an interrogation which was every bit as unhelpful as he'd been led to believe.

"Okay," said a French-sounding voice. "When did this start?"

"Yesterday morning, about five."

The man answering wasn't CIA. An interrogator trained at Langley would have said "O five hundred." The agent listening to the recording while simultaneously skimming a transcript to check its accuracy was glad of that. A few of the things the voice had been saying made Charlie very nervous indeed.

On a pad in front of him sat his notes. Little more than a handful of words and none of these rang any bells. A folder from the office stood open next to the notepad. The only memo inside announced that the CIA, the FBI and the NSA had no record of this man's fingerprints but that searches at a local level were being instigated. Interpol had also been alerted, a P13 going out to all European forces.

The hotel room was larger than Charlie had expected, with a bathroom off to one side, a simple desk in the main room and a television that managed to get half a dozen channels, most of them in Arabic.

"And what happened at five?" The French accent probably counted for little. Almost every doctor who spoke English in North Africa spoke it with a French accent, such were the accidents of history.

"Oh," said the American voice. "We injected another thirty milligrams of psilocybin..."

Downing his fifth coffee of the morning, Charlie Bilberg skimmed the next fifteen pages of transcript, barely reading the medical examination and the part where the doctor gave her permission for "Prisoner Zero's" interrogation to continue. (So someone at the Langley press office had thoughtfully labelled their captive. Charlie had his own views about giving catchy labels to criminals. As far as he was concerned it only encouraged them.)

Charlie jumped the recorder forward to the last intelligible block of answers and lit his first cigarette of the day, drawing smoke into his lungs.

"Who helped you?"

"Malika."

"Who's Malika?"

"Someone Moz knew."

Both names were currently being fed into the NSA system. If this produced no leads then the names would be passed to the European database in Brussels. Charlie was in favour of releasing them now at local level, but this had been overruled by Paula Zarte herself, everybody's new boss at Langley.

Two odd numbers added together always made an even. Two evens added together never made an odd. If a number is divisible by eleven the sum of its alternate digits is always equal, say 121 (apart from when zero messed up the sequence). It was irrelevant if the first 119 decimal places of vacuum energy exactly cancelled because it was what happened with the 120th that mattered...

There was no end to the information that Prisoner Zero apparently wanted to share. Speed-dialling a contact he'd been given at the NSA, Charlie zoned out a block of pure cracker-box maths while listening to his cell phone go unanswered.

"Chosen of what?" said a voice, when Charlie tuned in again.

"Of heaven..."

A sound, like someone sighing. "And what exactly is that supposed to mean?"

The silence which followed was broken by the flick of a lighter, the old-fashioned kind, and an animal-like howl.

"Well?"

"Incomprehensible" read an anonymous, hand-scrawled note next to the relevant section of transcript. Not that Charlie Bilberg needed this. The exact time of each statement was printed in the margin. A gap of eighteen minutes occurred between that question and its answer. The hand-scrawled note recorded that the prisoner was conscious during this entire period and was not undergoing any additional form of heavy questioning.

The time track was designed to make sure any taped confession would stand up in court. The Agency could do without some judge throwing out key evidence on the basis that most of it was cut and paste.

Personally, Charlie thought that using a time track was an excellent idea, although he was in a minority. He wasn't hopelessly naïve, however. Agent Bilberg had a good idea of exactly what had been done to Prisoner Zero before the man arrived at a point where he was prepared to make his statement.