Holmes frowned. 'Such as, sir?’

'Such as its provenance, its advanced years. What would you say, 1973? '74? Billy Cunningham wasn't even born in 1974. So what's this doing in his wardrobe beside up to-date scud mags and football programmes?’

He waited. 'Answer came there none.’

Holmes looked sullen; an annoying trait whenever Rebus showed him up. But Clarke was ready. 'We'll get. Orkney police to check, sir, always supposing the Orkneys possess any police.’

'Do that,' said Rebus.

Like a rubber ball, he thought as he drove, I'll come bouncing back to you. He'd been summoned back to Fettes by DCI Kilpatrick. In his pocket there was a message from Caroline Rattray, asking him to meet her in Parliament House. He was curious about the message, which had been taken over the phone by a Detective Constable in the Murder Room. He saw Caroline Rattray as she'd been that night, all dressed up and then dragged down into Mary King's Close by Dr Curt. He saw her strong masculine face with its slanting nose and high prominent cheekbones. He wondered if Curt had said anything to her about him… He would definitely make time to see her.

Kilpatrick had an office of his own in a corner of the otherwise open-plan room used by the SCS. Just outside it sat the secretary and the clerical assistant, though Rebus couldn't work out which was which. Both were civilians, and both operated computer consoles. They made a kind of shield between Kilpatrick and everyone else, a barrier you passed as you moved from your world into his. As Rebus passed them, they were discussing the problems facing South Africa.

'It'll be like on Uist,' one of them said, causing Rebus to pause and listen. 'North Uist is Protestant and South Uist is Catholic, and they can't abide one another.’

Kilpatrick's office itself was flimsy enough, just plastic partitions, see-through above waist height. The whole thing could be dismantled in minutes, or wrecked by a few judicious kicks and shoulder-charges. But it was definably an office. It had a door which Kilpatrick told Rebus to close. There was a certain amount of sound insulation. There were two filing-cabinets, maps and print-outs stuck to the walls with Blu-Tak, a couple of calendars still showing July. And on the desk a framed photograph of three grinning gap-toothed children.

'Yours, sir?’

'My brother's. I'm not married.’

Kilpatrick turned the photo around, the better to study it. `I try to be a good uncle.’

'Yes, sir.’ Rebus sat down. Beside him sat Ken Smylie, hands crossed in his lap. The skin on his wrists had wrinkled up like a bloodhound's face.

'I'll get straight to the point, John,' said Kilpatrick. 'We've got a man undercover. He's posing as a long-distance lorry driver. We're trying to pick up information on arms shipments: who's selling, who's buying.’

'Something to do with The Shield, sir?’

Kilpatrick nodded. 'He's the one who's heard the name mentioned.’

'So who is he?’

'My brother,' Smylie said. 'His name's Calumn.’

Rebus took this in. 'Does he look like you, Ken?’

'A bit.’

`Then I dare say he'd pass as a lorry driver.’

There was almost a smile at one corner of Smylie's mouth.

'Sir,' Rebus said to Kilpatrick, 'does this mean you think the Mary King's Close killing had something to do with the paramilitaries?’

Kilpatrick smiled. 'Why do you think you're here, John? You spotted it straight off. We've got three men working on Billy Cunningham, trying to track down friends of his. For some reason they had to kill him, I'd like to know why.’

'Me too, sir. If you want to find out about Cunningham, try his flatmate first.’

'Murdock? Yes, we're talking to him.’

'No, not Murdock, Murdock's girlfriend. I went round there when they reported him missing. There was something about her, something not quite right. Like she was holding back, putting on an act.’

Smylie said, 'I'll take a look.’

'Her and her boyfriend both work with computers. Think that might mean something?’

'I'll take a look,' Smylie repeated. Rebus didn't doubt that he would.

'Ken thinks you should meet Calumn,' Kilpatrick said.

Rebus shrugged. 'Fine by me.’

'Good,' said Kilpatrick. 'Then we'll take a little drive.’

Out in the main office they all looked at him strangely, like they knew precisely what had been said to him in Kilpatrick's den. Well, of course they knew. Their looks told Rebus he was resented more than ever. Even Claverhouse, usually so laid back, was managing a snide little grin.

DI Blackwood rubbed a smooth hand over the hairless crown of his head, then tucked a stray hair back behind his ear. His tonsure was positively monasterial, and it bothered him. In his other hand he held his telephone receiver, listening to someone on the line. He ignored Rebus as Rebus walked past.

At the next desk along, DS Ormiston was squeezing spots on his forehead.

'You two make a picture,' Rebus said. Ormiston didn't appear to get it, but that wasn't Rebus's problem. His problem was that Kilpatrick was taking him into his confidence, and Rebus still didn't know why.

There are lots of warehouses in Sighthill, most of them anonymous. They weren't exactly advertising that one of them had been leased by the Scottish Crime Squad. It was a big old prefabricated building surrounded by a high wire fence and protected by a high barred gate. There was barbed wire strung out across the top of the fence and the gate, and the gatehouse was manned. The guard unlocked the gate and swung it open so they could drive in.

'We got this place for a song,' Kilpatrick explained. 'The market's not exactly thriving just now.’

He smiled. 'They even offered to throw in the security, but we didn't think we'd need any help with that.’

Kilpatrick was sitting in the back with Rebus, Smylie acting as chauffeur. The steering wheel was like a frisbee in his paws. But he was a canny driver, slow and considerate. He even signalled as he turned into a parking bay, though there was only one other car in the whole forecourt, parked five bays away. When they got out, the Sierra's suspension groaned upwards. They were standing in front of a normal sized door whose nameplate had been removed. To its right were the much bigger doors of the loading bay. From the rubbish lying around, the impression was of a disused site. Kilpatrick took two keys from his pocket and unlocked the side door.

The warehouse was just that, no offices or partitions off, just one large space with an oily concrete floor and some empty packing cases. A pigeon, disturbed by their entrance, fluttered near the ceiling for a moment before settling again on one of the iron spars supporting the corrugated roof. It had left its mark more than once on the HGV's windshield.

'That's supposed to be lucky,' said Rebus. Not that the articulated lorry looked clean anyway. It was splashed with pale caked-on mud and dust. It was a Ford with a UK licence plate, K registration. The cab door opened and a large man heaved himself out.

He didn't have his brother's moustache and was probably a year or two younger. But he wasn't smiling, and when he spoke his voice was high-pitched, almost cracking from effort.

'You must be Rebus.’

They shook hands. Kilpatrick was doing the talking.

'We impounded this lorry two months back, or rather Scotland Yard did. They've kindly loaned it to us.’

Rebus hoisted himself onto the running-plate and peered in the driver's window. Behind the driving seat had been fixed a nude calendar and a dog-eared centrefold. There was space for a bunk, on which a sleeping bag was rolled up ready for use. The cab was bigger than some of the caravans Rebus had stayed in for holidays. He climbed back down.