He rose from the box and walked to the edge of the lorry, then dropped to the ground and turned towards them. 'You haven't proved anything to me. If you want to try your act with someone else, be my guests.’

'You cold bastard,' Abernethy said. He made it sound like a compliment. He walked to the edge of the lorry and faced Kilpatrick, then slowly began to pull his shirt out from his trousers. He lifted it up, showing bare flesh and sticking plasters and wires. He was miked up. Kilpatrick stared back at him.

'Anything to add, sir?’

Abernethy said. Kilpatrick turned and walked away. Abernethy turned to Rebus. 'Quiet all of a sudden, isn't it?’

Rebus leapt from the lorry and walked briskly to the door. Kilpatrick was getting into his car, but stopped when he saw him.

'Three murders so far,' Rebus said. 'Including a police officer, one of your own. That's a madness of the blood.’

'That wasn't me,' Kilpatrick said quietly.

'Yes, it was,' Rebus said. 'There'd be none of it without you.’

'I don't know how they got to Calumn Smylie.’

'They hack into computers. Your secretary uses one.’

Kilpatrick nodded. 'And there's a file on the operation in the computer.’

He shook his head slowly. 'Look, Rebus…’

But Kilpatrick stopped himself. He shook his head again and got into the car, shutting the door.

Rebus bent down to the driver's-side window, and waited for Kilpatrick to wind it down.

'Abernethy's told me what it's about, why the loyalists are suddenly arming themselves. It's Harland and Wolff.’ This being a shipyard, one of the biggest employers in the province, its workforce predominantly Protestant. 'They think it's going to be wound up, don't they? The loyalists are taking it as a symbol. If the British government lets Harland and Wolff go to the wall, then it's washing its hands of the Ulster Protestants. Basically, it's pulling out.’

Hard to know whether Kilpatrick was listening. He was staring through the windscreen, hands on the steering wheel. 'At which point,' Rebus went on anyway, 'the loyalists are set to explode. You're arming them for civil war. But worse than that, you've armed Davey Soutar. He's a walking anti-personnel mine.’

Kilpatrick's voice was hard, unfeeling. 'Soutar's not my problem.’

'Frankie Bothwell can't help. Maybe he could control Soutar once upon a time, but not now.’

'There's only one person Soutar respects,' Kilpatrick said quietly, 'Alan Fowler.’

'The UVF man?’

Kilpatrick had started the engine.

'Wait a minute,' said Rebus. As Kilpatrick moved off, Rebus kept a grip of the window-frame. Kilpatrick turned to him.

'Nine tonight,' he said. 'At the Gar-B.’

Then he sped out of the compound.

Abernethy was just behind Rebus.

'What was he telling you?’ he asked.

'Nine o'clock at the Gar-B.’

'Sounds like a nice little trap to me.’

'Not if we take the cavalry.’

'John,' Abernethy said with a grin, 'I've got all the cavalry we'll need.’

Rebus turned to face him. 'You've been playing me like a pinball machine, haven't you? That first time we met, all that stuff you told me about computers being the future of crime. You knew back then.’

Abernethy shrugged. He pulled up his shirt again and started to pull off the wires. 'All I did was point you in the general direction. Look at the way I got on your tits that first time. That's how I knew I could trust you. I nettled you and you let it show. You'd nothing to hide.’

He nodded to himself. 'Yes, I knew, I've known for a long time. Proving it was the bugger.’

Abernethy looked at the compound gates. 'But Kilpatrick's got enemies, remember that, not just you and me any more.’

'What do you mean?’

But Abernethy just winked and tapped his nose. 'Enemies,' he said.

Rebus had pulled Siobhan Clarke off the Moncur surveillance and put her on to Frankie Bothwell. But Frankie Bothwell had disappeared. She apologised, but Rebus only shrugged. Holmes had kept with Clyde Moncur, but Moncur and his wife were off on some bus tour, a two-day trip to the Highlands. Moncur could always get off the bus and double back, but Rebus discontinued the tail anyway.

'You seem a bit glum, sir,' Siobhan Clarke told him. Maybe she was right. The world seemed upside down. He'd seen bad cops before, of course he had. But he had never before seen anything like Kilpatrick's lack of an explanation or a decent defence. It was as if he didn't feel he needed one, as if he'd just been doing the right thing; in the wrong way perhaps, but the right thing all the same.

Abernethy had told him how deep the suspicions went, how long they'd been accumulating. But it was hard to investigate a policeman who, on the surface, seemed to be doing nearly everything right. Investigation required cooperation, and the co-operation wasn't there. Until Rebus had come along.

At the Gar-B lock-ups, outside the blocks of flats, police and Army experts were opening doors, just in case the stolen cache was inside one of the garages. Door to door inquiries were going on, trying to pin down Davey's friends, trying to get someone to talk or to admit they were hiding him. Meantime, Jamesie MacMurray was already being charged. But they were minnows, their flesh not enough to merit the hook. Kilpatrick, too, had disappeared, Rebus had phoned Ormiston and found that the CI hadn't returned to his office, and no one answered at his home.

Holines and Clarke returned from the warrant search of Soutar's home, Holmes toting a plain cardboard box, obviously not empty. Holmes put the box on Rebus's desk.

‘Let's start,' Holmes said, 'with a jar of acid, carefully concealbd under Soutar's bed.’

'His mother says he never lets her in to clean his room,' Clarke explained. 'He's got a padlock on the door to prove it. We had to break the lock. His mum wasn't best pleased.’

'She's a lovely woman, isn't she?’ said Rebus. 'Did you meet the dad?’

'He was at the bookie's.’

'Lucky for you. What else have you got?’

'Typhoid probably,' Holmes complained. 'The place was like a Calcutta rubbish tip.’

Clarke dipped in and pulled out a few small polythene bags; everything in the box had been wrapped first and labelled. 'We've got knives, most of them illegal, one still with what looks like dried blood on it.’

Some of it Calumn Smylie's blood, Rebus didn't doubt. She dipped in again. 'Mogadon tablets, about a hundred of them, and some unopened cans of cola and beer.’

'The Can Gang?’

Clarke nodded. 'Looks like it. There are wallets, credit cards… it'll take us two minutes to check. Oh, and we found this little booklet.’

She held it up for him. It was poorly Xeroxed, with its A4-sized sheets folded in half and stapled. Rebus read the title.

'The Total Anarchy Primer. Wonder who gave him this?’

'Looks like it's been translated from another language, maybe German. Some of the words they couldn't find the English for, so they've left them in the original.’

'Some primer.’

'It tells you how to make bombs,' said Clarke, 'in case you were wondering. Mostly fertiliser bombs, but there's a section on timers and detonators, just in case you found yourself with any plastique.’

'The perfect Christmas gift. Are they checking the bedroom for traces?’

Holmes nodded. 'They were at it when we left.’

Rebus nodded. A special forensic unit had been sent in to test for traces of explosive materials. The same unit had been working at the MacMurray lock-up. They knew now that the garage had held a quantity of plastic explosive, probably Semtex. But they couldn't say how much. Usually, as one of the team had explained, Semtex was quite difficult to prove, being colourless and fairly scentless. But it looked like Soutar had been playing with his toys, unwrapping at least one of the packages the better to have a look at it. Traces had been left on the surface of the workbench.