‘He was caught trousers-up,’ Rebus reminded his superior.

‘Besides,’ added Watson, ‘Mr Jack, too, has his alibis.’ He read from a sheet of paper. ‘Constituency meeting in the morning. Round of golf in the afternoon – corroborated by his playing partner and checked by Detective Constable Broome. Then a dinner appointment where he made a speech to eighty or so fine upstanding members of the business community in Central Edinburgh.’

‘And he drives a white Saab,’ Rebus stated. ‘We need to check car colours for everyone involved in the case, all Mrs Jack’s friends and all Mr Jack’s.’

‘I’ve already put DS Holmes on to it,’ said Lauderdale. ‘And forensics say they’ll have a report on the BMW ready by morning. I’ve another question though.’ He turned to Rebus. ‘Mrs Jack was, apparently, up north for anything up to a week. Did she stay all that time at Deer Lodge?’

Rebus had to give Lauderdale credit, the bugger had his thinking cap on today. Watson was nodding as though he’d been about to ask the selfsame thing, but of course he hadn’t. Rebus had thought about it though.

‘I don’t think so,’ he said. ‘I do think she spent some time there, otherwise where did the Sunday papers and the green suitcase come from? But a whole week . . .? I doubt it. No signs of recent cooking. All the food and cartons and stuff I found were either from one party or another. There had been an attempt to clear a space on the living room floor, so one person or maybe two could sit and have a drink. But maybe that goes back to the last party, too. I suppose we could ask the guests while we’re fingerprinting them . . .’

‘Fingerprinting them?’ asked Watson.

Lauderdale sounded like an exasperated parent. ‘Purposes of elimination, sir. To see if any prints are left that can’t be identified.’

‘What would that tell us?’ Watson said.

‘The point is, sir,’ commented Lauderdale, ‘if Mrs Jack didn’t stay at Deer Lodge, then who was she with and where did she stay? Was she even up north all that time?’

‘Ah . . .’ said Watson, nodding again as though understanding everything.

‘She visited Andrew Macmillan on the Saturday,’ added Rebus.

‘Yes,’ said Lauderdale, getting into his stride, ‘but then she’s next seen on the Wednesday by that yob at the farm. What about the days in between?’

‘She was at Deer Lodge on the Sunday with her newspapers,’ Rebus said. Then he realized the point Lauderdale was making. ‘When she saw the story,’ he continued, ‘you think she may have headed south again?’

Lauderdale spread out his hands, examining the nails. ‘It’s a theory,’ he said, merely.

‘Well, we’ve plenty bloody theories,’ said Watson, slapping one of his own much meatier hands down on the desk. ‘We need something concrete. And let’s not forget friend Glass. We still want to talk to him. About Dean Bridge if nothing else. Meanwhile . . .’ he seemed to be trying to think of some path they might take, of some instructions or inspiration he might give. But he gave up and swigged back his coffee instead. ‘Meanwhile,’ he said at last, while Rebus and Lauderdale waited for the imparted wisdom, ‘let’s be careful out there.’