Dripping-Tears Tat and five of his mates straightened, eyes widening. Only Rotating-Swastika Guy failed to react, immersed in mouthing off to the lad behind the till. But the others were frozen, their brains processing unconscious alarms, primal senses re-evaluating the violent potential here.

One of them grabbed hold of Rotating-Swastika and yanked him back.

"Come on, you d.i.c.k."

Those nearest the door were already leaving.

"What?"

"Police officer, come on."

Then they filed out, and were gone.

Good.

Except that part of him thought the opposite, that it was an aching shame they had denied him the opportunity of the dance, to let loose the reptile inside, the lizard-brain that fought with logic, and the primate layer that knew the joy of blood because a smile and a scream are predator's expressions, the baring of teeth and the spurting ecstasy of ripping and rending, hitting and twisting, smashing knee-joints, slamming skulls into red oblivion.

He wanted to tear them apart.

[ TWENTY ].

The guy behind the till was called Gopan. After thanking Josh, he called out all his family so they could give thanks, too. Three people came out from the kitchen: a large man called Uncle Rajesh, skinny brother Sanjeev, and the tired girl who served the food: Gopan's sister, Mina.

"You're all welcome," said Josh. "And look, you've already got spyb.a.l.l.s. Why don't you get two more cams, and rearrange them there and there."

"Ah." Sanjeev's eyes were bright as he nodded, understanding the geometry. "Very good idea."

"Add an alarm that you can trigger," Josh pointed at Gopan's phone. "Then buy a monthly call-out plan from one of the local security firms. Except check at the police station before you deal with anyone."

"Will you be there?" asked Gopan.

"I'm not a police officer. They were mistaken."

"Ah. But you were looking for someone."

"I'm working for the boy's father, who's worried."

"Oh. Would you show us the picture again?"

Josh brought up Richard's image, and turned the phone to Gopan. This time Gopan frowned for a longtime before shaking his head.

"I'm really sorry. Uncle Rajesh?"

The big man took a look. "No, sorry."Sanjeev had been peering at it over the others' shoulders. "I don't think so."

But Mina gave a tilting nod.

"You recognise him?" said Josh.

"With Opal." Her voice was less dull than before. "Walking with Opal."

"Who's?"

"Local girl," said Sanjeev. "Comes here sometimes, not often. Chats with Mina."

"When did you last see Opal?"

"Days ago." Mina looked down at the floor. "A few days."

"You know where she lives? Or which school she goes to?"

Mina shook her head.

"Sanjeev?" asked Josh. "Any ideas?"

"Sorry."

"That's OK. I've got a name. You probably don't know her surname?"

"Afraid not."

"OK. Thanks, everyone."

"Thank you!"

Smiles and nods and waves carried him to the door. He went out onto the street grinning, remembering to check for signs of the gang waiting in ambush, but seeing only a clear ordinary street, safe to walk along. After some eight or ten paces, he stopped, remembering Viv at the shelter, and what she had said just a few minutes back: "The lad might be friendly with some gekrunners."

He turned and went back in. The family were still standing among the tables, discussing what had happened.

"Mina, I don't suppose this Opal is a gekrunner, is she?"

Mina's smile was big as she nodded.

"Jumps," she said. "Somersaults and things. She's brilliant."

"So are you," Josh told her. "So are you."

Uncle Rajesh hugged her, and her grin reminded Josh of Christmas and getting just the present you wanted, and had thought you would never have.

Josh waved a salute and left.

Richard looked up from the floor, sponge in hand, as Opal entered the shop, unhitching a backpack from her shoulder.

"Whoah, bad smell," she said. "Who threw up? Cal told Brian to keep out the winos."

"It was me. Again."

"Oh."

"Brian's getting some sort of spray, says it'll clear the air."

He rinsed the sponge in the bucket, and wiped some more. There was nothing left to clean up, nothing visible, but Opal was right: the stench remained.

"Hey, Opal." Brian came in from the back, a huge yellow aerosol in hand. "Stand by for some biochemical warfare. This is powerful stuff."

"Maybe I should open the front door."

"Probably." Brian looked down at Richard. "You must have started wearing a hole in the floor. It won't get cleaner than that."

"Sorry."

"That's the seventy-seventh time he's apologised," Brian told Opal. "I've been counting."

"Not that many," said Richard.

Opal asked, "What did Cal say?""He hasn't been in, thank G.o.d." Brian waved the aerosol, sloshing the contents. "Let's keep him none the wiser."

"Oh, right. He's probably at South Bank."

"And you're here about tonight." Brian pointed at her backpack. "Equipment check, right?"

"Uh-huh. So, you want me to open this door? Cause I'd like to breathe."

"Sorr" Richard stopped himself.

"I've a better idea," said Brian. "Opal, close up, and we'll go in the back room."

She locked the shop door and tapped the b.u.t.tons on the door frame. The gla.s.s shone with the word CLOSED, in reverse.

"Come on." She took hold of Richard's sleeve. "Let's get out of here."

He picked up the bucket, dropped the sponge inside, and let her lead him out of the room. From behind came the sound of Brian sucking in a breath, followed by the prolonged hissing of the spray. Then Brian was pushing him into the back room and slamming the door shut.

"That is evil, evil stuff. But when it blows away later, it'll take any other stink with it."

Opal tapped Richard on the forehead. "Don't say sorry again."

He grinned and shook his head.

"All right," said Brian. "Take out your gear, and let's take a look."

Around the workshop stood several wooden workbenches with clamps and tools, covered with bits of bicycles and other equipment, not to mention sawdust, metal filings and the heavy smell of oil, currently contaminated with sharp chemical scents leaking through the door. Opal made room on the least cluttered bench, then laid her backpack on top. From the pack, she extracted a pair of goggles and what looked like an ordinary white sweatshirt.

Brian used a clamp to hold a spyball camera in place behind the goggles. Then, even though there were four wallscreens in place, he unfolded a small display and positioned it in front of the goggles. Then he tapped his phone, and the screen lit up, showing a rotating abstract pattern.

"Test pattern. Opal, let's have the blackout cloth."

She rummaged on a shelf, then backed out bearing a folded black cloth. It looked flimsy as she opened it out, spreading it with Brian's help over the workbench, forming a tent over spyball, goggles, and the screen with the test pattern.

"The cloth's one hundred percent opaque," said Brian. "Lightweight but optically dense."

"Oh." Richard looked at the wall screen. "You're testing the goggle's response."

"Bright lad." Brian pointed his phone at a wallscreen, causing it to show numeric data plus a copy of the changing test pattern. "Now we cross-check the calibration."

"It's all right, isn't it?" said Opal.

"Your long-wavelength response is a little skewed." Brian pointed. "So it ain't perfect. But safe enough to use."

"Good."

Richard looked from one to the other. "Use for what?"

"Night run," said Opal.

"Tonight." Brian grinned. "You'll see."

"And the shirt." Opal laid the sweatshirt on the bench, clipped a thin cable to the fabric, and held out the other end of the cable. It had a phone connector. "You got the downloads ready?"

"Uh-huh. How's it working at the moment?"

"All right, I think."

"Let's see."

Opal did something, then star-shaped splashes of sapphire blue and glimmering emerald radiated from the centre of the shirt, pulsing over and over. After a moment, the red outline of a gekrunner began tumbling through extreme gymnastics across the blazing background.

"Wow," said Richard.

"It's so old." Opal looked pleased anyway. "Need something new for tonight."

"I've got just the thing," said Brian, taking the cable. "Switch it off, and I'll run the download."

"Lots of bright colours?"