Not all of it involved violence.

Running back, Charlie listened carefully, one hand against his ear to cut out noise from the room's overhead air-conditioning. "Chosen of heaven," that was definitely what the prisoner said.

On his wall behind the dressing table was a socket labelled "5-star hotelNet," so he plugged in his Sony Vaio and waited for the little laptop to recognize the connection, then he fed in his room number and Amex details. The price was a hundred dirham a day, about ten dollars.

Google gave him a Baptist site, chapter five of Ivanhoe by Walter Scott, some mediocre poetry, a ministry dedicated to the New Holy Cross of the Rosy Dawn and a handful of references to assorted verses from the Old Testament, none of which looked likely.

Shutting down his laptop, Charlie went back to the recording, matching what was said word-for-word against the transcript in front of him.

"Like Equal of Heaven, only that's the monkey..." The answer, like the question, was in English, its slurring most probably explained by the medical prescriptions stapled to the back of the transcript.

Three hallucinogens, two sedatives and a painkiller mostly prescribed in childbirth but also used for lowering inhibitions. One of the sedatives and all of the hallucinogens were illegal in the US, which was fine because this wasn't the US and the various doctors who'd signed the prescriptions were not American. Charlie Bilberg had been careful to check.

"What makes you Chosen?"

"I'm not..."

"You just said you were."

The reply, when it came, was too muffled to make out, the transcript using a row of Xs to show that this line of dialogue was beyond deciphering.

"This is pointless," said a voice Charlie hadn't heard before. "The man barely knows what he's saying."

"More chance of getting the truth."

A snort, but the voice fell silent as the first man went back to his questions. "This group of yours, who leads them?"

"Group?"

"Who leads the Chosen of Heaven?" The way the interrogator snarled this question made clear his belief that CoH were terrorists on a level with al Qaeda, the Baathist Party or the Taliban. "Well?"

"Only one person is chosen," said Prisoner Zero. "And only the darkness knows how he is selected."

The silence which followed this made clear that it was not the answer the interrogator had wanted or been expecting.

The summer Moz turned seven a stray word crawled into his ear and ate its way to his brain, where it set up a nest that spawned questions, which tunnelled into the jellied ignorance inside his head, changing the way he thought and saw and smelt things.

He began to see patterns behind the patterns to be found in zellije work on the walls of mosques and public fountains. Certain tile formations repeated and mirrored themselves in ways people did not at first realize. A beating from an imam taught the one-armed boy that not everyone wished to have this general ignorance pointed out, so he learnt to lie.

From a scrap of guidebook found behind a bush on the edge of Jardin Aguedal he learnt that his home was seventeen hundred feet above sea level and forty miles from the High Atlas, whose peaks rose another twelve thousand feet. Eight miles of wall circled the Red City, broken by twelve great gates, each bab giving its name to a quartier of Marrakech. The circling wall was made of pisé, mud mixed with lime and straw. Moz wasn't too sure what miles and feet were, so he added this to his list of questions that needed answering.

Shit smeared the page, but Moz didn't mind. Having scraped the square of paper clean, he washed it in a fountain and pegged it on his mother's clothes line to dry in the sun. These days it lived in a small cardboard box under his bed along with three Spanish coins, a plastic Biro that no longer worked and an Opinel knife with a broken blade.

No one he asked knew how long a mile was.

Moz forgot to do the jobs his mother gave him and cared so little that he barely noticed her irritation turn from anger to worry. He ate less, slept less and tasted nothing. Eventually he ran out of people to ask. That was when he realized his world was really quite small.

It was Sidi ould Kasim, the old army corporal who lived on the ground floor, who told Moz he'd been infected. Sat on his wooden stool outside the tiny house in Derb Yassin on the edge of the old Jewish quarter, he scowled at the one-armed child and sipped at a tea glass which contained three mint leaves floating in neat marc, brandy distilled from little more than pips and skin. Everyone in the Mellah knew what his glass contained but no one mentioned it. The Corporal's temper saw to that.

Corporal ould Kasim, Malika, Moz's mother and Moz lived in the same narrow house, where the dark alley of Derb Yassin intersected with an even tighter passage, one too decrepit and dark to merit a name or even appear on a map. The Corporal and his daughter occupied the downstairs while Moz and his mother occupied both of the rooms upstairs and everyone shared the roof as somewhere to dry washing or store furniture so worthless as to be unsellable.

"I said," ould Kasim demanded, "who told you about miles anyway?"

No one told me, Moz wanted to say. I discovered them for myself from a nasrani's shit scraper, when I was meant to be collecting skhina.

Skhina were the pots of eggs, meat and vegetables which got baked every Friday for the Yehoudia still living in the Mellah. Moz worked odd days for Maallan Mohammed, a master baker who owned the nearest bread oven and the maallan charged double for Jews.

This was not a reply Moz could give and besides, feet and miles were just unspecified measurements he'd stumbled over and kept stumbling, as Moz always did until he found his answers.

"Are you deaf as well as stupid?"

There were some who said ould Kasim was a police informer and a few who believed he was nosy by instinct. Most just thought he'd never recovered from his wife catching a fever. Because Leila was dead, when something went wrong he hit his daughter instead.

"He's not stupid," Moz's mother said, coming out to collect her son from where he stood in the street, too afraid to walk past the old Corporal. "He just sees things we don't..."

Sidi ould Kasim could not understand why Moz's mother would not marry him. She was foreign, ill and poor, a German woman who no longer even wrote to her family. Whereas he had a pension from Paris, a city he'd help liberate, and owned a Croix de Guerre as proof. It was a small pension by French standards but more than enough to keep a man living in this city. Certainly enough to ensure that any woman he married would never need to work again.

All the same, Dido kept refusing and the old man with his stool, filthy jellaba and frayed boots took her refusals badly. He blamed Moz and in this ould Kasim was right. If not for her son Dido would probably have married the Corporal to get away from what her life had become.

"All he does is dream," Sidi ould Kasim told the woman. "Dream stupid dreams and make up lies."

Moz shook his head.

"And what's that he's got now?"

"Just a magazine," Moz protested. "I found it."

"American muck," the Corporal said crossly. "Soon you won't be any use at all." Taking the magazine from Moz's hand, he opened it at random. A half-naked negro with her brat, a man wearing a glass helmet and a boy holding a Molotov cocktail.

"You shouldn't let him read this," he told Dido, tearing that week's issue of Time in two. And so Moz missed knowing that Apollo had reached the moon and famine had killed thousands in Biafra while violence stalked the slums of Northern Ireland.