A trawl of the Mellah by the police had revealed no clue to the suspect's current whereabouts and extensive questioning of his known associates had produced so little information about the suspect's recent activities that this was suspicious in itself. Katie Petrov read this twice, to make sure she understood what was being said.

On the basis of the statement a warrant for the boy's arrest on sight had been issued by the Marrakchi police and then allowed to gather dust. Both the arrest warrant and the sworn statement were signed by a Major Abbas.

"What do you think?"

"The interest is in the gaps," said Katie Petrov. "If I got sent this back home I'd have returned it and demanded sight of the real thing. And I'd refuse to start work until the real thing arrived."

Professor Mayer nodded. "That's what I've done," she said. "Although I'm not sure how much we'll get."

Flicking through the three photographs, Katie forced herself to glance again at the final one. There existed crime-scene shots of Texas lynchings that showed less tissue damage.

"Check the file again," suggested Petra Mayer.

Three photographs, an arrest warrant, a sworn statement, a tatty strip of fingerprints lifted from a pocket knife found at the crime scene, a crudely drawn map of the wasteland marking where the girl's body was found and a report from the coroner.

"What am I missing?" Katie Petrov asked.

"These," Professor Mayer said, tossing across a cromalin of a second set of fingerprints, each one neatly positioned in a different-coloured box. The cromalin was new and still smelt of chemicals. The fingerprints came from the police HQ in Amsterdam and the name scrawled at the top of the original sheet was Jake Razor.

"Don't tell me..."

Katie held up the strip of fingerprints lifted from the crime scene in Marrakech and compared them to prints on the page in front of her. She didn't really need to be told what she would find. The American minimum for matching points was ten, the European standard was set at sixteen.

To Katie's gaze it looked like the match between Prisoner Zero's prints, those taken from the Marrakchi knife and the prints for Jake Razor from the Amsterdam drug clinic had at least eighteen points of similarity, maybe more.

"Still think he's sane?" Professor Mayer asked.

The jets came in low over the water, three in all. Each one as flat as a manta ray and utterly silent, their uncloaking timed for when the already sinking yacht reached midway along the gorge.

So far as Tris could tell all three were completely transparent, as if made from glass or carved from ice, and they materialized just as the shell of All Tomorrow's Parties finally tipped on its side, expelling Tris from her doorway in a massive fart of bubbles and river water.

Sweeping low, the jets banked hard and came back on themselves, targeting the river where the yacht had been. And suddenly there was no water and no river and no yacht, just emptiness, which filled as the river roared back in.

Either the jets really didn't see Tris or they didn't care. Or else, Tris told herself, as the current carried her rapidly downstream towards some rocks, they simply weren't looking for a girl with a blue marble in her mouth and pockets full of water.

The jacket was a classic, expensive probably, with an inner lining that clung to her body no matter how oversized the garment looked on the outside and a waist buckle that was busy trying to do itself up. Unfortunately the wrists were still significantly too big for her and the pockets seemed to be expanding to make space for more water.

Tris reached for the buckle.

Once she'd extracted the marble from her mouth and finished coughing up river, she had another go. Only this time, Tris took a hurried breath before dunking herself and tugged hard at the buckle. When the buckle refused to budge, Tris tried pulling the jacket over her head, which would have worked if only the lining didn't keep shaping itself around her to provide warmth. She was being killed by the thing's blind and stupid kindness.

"Shit...

"Prick...

"Pudenda..."

The one advantage, probably the only advantage, to being alone in the middle of nowhere was that her grandmother wasn't around to slap her if she swore. Which was just as well, as Tris was rapidly reaching levels of vocabulary even Doc Joyce didn't know she possessed.

"Fuck this," Tris said. And she yanked at the buckle so hard it made her knuckles almost pop with the effort.

"About time."

Quite how Tris made it over the rocks unscathed she didn't know until later, when she rolled herself onto a gravel bank under the gaze of broken grey cliffs and realized she hadn't made it through unscathed at all. One shoulder was a mess of bruises and her left heel had been sliced near the arch, cut open by a stone. Bleached skin gaped on both sides of the cut.

Staring too hard at the wound made Tris feel sick so she stopped looking, pulled herself completely out of the water and sat with her back to the cliff. It was time to work out where she was and relate that to where she should be, which was infiltrating the Forbidden City with the express purpose of killing the Chuang Tzu.

The gravel where Tris sat was built up on the quiet side of the river, while on the other bubbling foam scoured against a rock wall. This was the way it worked, Tris realized, looking upriver towards a different bend and at another bend beyond that, tracking the course she'd taken. The river roared into the bends and threw up gravel on the quiet side, reversing sides when the gorge curved a different way.

Her own bank began fifty paces behind her as a narrow strip of shingle bellied out into the river and then narrowed again to nothing a hundred paces ahead. Walking to safety along the edge of the river was definitely out.

And that was a problem, because the rock-face behind Tris's back was sheer beyond climbing, even for Tris, and both sides of the gorge seemed to rise endlessly through the charcoal of cliffs to a belt of green before fading into a pale grey that rose like a watercolour wash above the tree line.

She was going to have to go back into the water, but first... Digging a thumbnail into the latex over her hip, Tris tried to rip the top half free from the bottom of her jump suit without messing everything up too much. All that happened was that the material tore and she ended up with an over-long top and a ridiculously low-slung pair of trousers.

Having done what she needed, Tris washed her hands in the river and yanked up her trousers, tying torn strips of latex together at both sides.

It was time to get wet again.

Tris wasn't sure when she first noticed the light in the sky. It might have been on her second night or the third. Whichever night it was, she'd got hungry enough not to care too much about anything but finding food. At the time Tris was trudging along a strip of shingle and expecting it to end in a return to the cold water. And at the point she realized the gravel was there for good, she was several klicks from where she'd last scrambled ashore and her cut foot was warm enough to hurt; although it would mend soon, her wounds always did.

Warmth and food, these weren't exactly thoughts, more the things that went through Tris's head as she climbed a shingle bank and found herself stumbling towards the light across rough grass.

When it moved, Tris froze.

The weapon Doc Joyce had given her was either at the bottom of the river or else broken into its constituent atoms, which seemed more likely. And the knife she usually carried was where she'd left it, on the side in Doc Joyce's surgery. He'd assured her that the blade would wake every alarm system on Chinese Rocks and he was undoubtedly right. All the same she missed its weight on her belt.