And the grieving husband? Kept well away from the media by protective friends and colleagues. But he was always available for interview by the police, when clarification of some point was required. While his father-in-law gave the media as many interviews as they needed, but kept his comments to the police succinct and scathing.

'What do you want to talk to me for? Find the bugger who did it, then you can talk all you want. I want the animal who did this put behind bars! Better make them bloody strong bars, too, otherwise I might just pull them apart and strangle the life out of the bugger myself!'

'We're doing what we can, believe me, Sir Hugh.'

'Is it enough though, that's what I want to know!'

'Everything we can…'

Yes, everything. Leaving just the one final question: Did anyone do it? Only Dr Curt could answer that.

Rebus packed an overnight bag. It was a large sports holdall, bought for him by Patience Aitken when she'd decided he should get fit. They'd enrolled together in a health club, bought all the gear, and had attended the club four or five times together. They'd played squash, been massaged, had saunas, encountered the plunge pool, gone swimming, survived the expensively equipped gymnasium, tried jogging… but ended up spending more and more time in the health club bar, which was stupid, the drinks being double the price they were at the pleasant-enough pub round the corner.

No longer a sports bag then, but these days an overnight bag. Not that Rebus was taking much this trip. He packed a change of shirt, socks and underwear, toothbrush, camera, notebook, a kagoul. Would he require a phrase book? Probably, but he doubted if one existed. Something to read though… bedtime reading. He found the copy of Fish out of Water and threw it in on top of everything else. The phone was ringing. But he was in Patience's flat, and she had her own answering machine. All the same…

He went through to the living room and listened as the message played. Then the caller's voice. 'This is Brian Holmes, trying to get in touch with -'

Rebus picked up the receiver. 'Brian, what's up?'

'Ah, caught you. Thought maybe you'd already headed for the hills.'

'I was just leaving.'

'Sure you don't want to drop by the station first?'

'Why should I?'

'Because Dr Curt is about to pronounce…'

The problem with drowning was that drowning and immersion were two entirely different things. A body (conscious or unconscious) might fall (or be pushed) into water and drown. Or an already dead body might be dumped into water as a means of concealment or to lead the police astray. Cause of death became problematical, as did time of death. Rigor mortis might or might not be present. Bruising on and damage to the body might be the result of rocks or other objects in the water itself.

However, froth from mouth and nose when the chest was pumped down on was a sign that the body was alive when it entered the water. So was the presence in the brain, marrow, kidney and so forth of diatoms. Diatoms, Dr Curt never tired of explaining, were micro-organisms which penetrated the lung membrane and would be pumped around the bloodstream by a still-beating heart.

But there were other signs, too. Silted matter in the bronchial tubes provided evidence of inhalation of water. A living person falling into water made attempts to grip something (a true-life 'clutching at straws') and so the hands of the corpse would be clenched. Washerwoman's skin, the shedding of nails and hair, the swelling of the body – all these could lead to an estimate of the amount of time the corpse had spent in the water.

As Curt pointed out, not all the relevant tests had been completed yet. It would be a few more days before the toxicology tests would yield results, so they couldn't be sure yet whether the deceased had taken any drink or drugs prior to death. No semen had been found in the vagina, but then the deceased's husband had provided information that the deceased 'had trouble' with the pill, and that her preferred method of contraception had always been the sheath…

Christ, thought Rebus, imagine poor old Jack being asked about that. Still, there might be even less pleasant questions to answer…

'What we have so far,' Curt said, while everyone begged him silently to get on with it, 'is a series of negatives. No froth from the mouth and nose… no silted matter… no clenched hands. What's more, rigor mortis would suggest that the body was dead prior to immersion, and that it had been kept in a confined space. You'll see from the photographs that the legs are bent quite unnaturally.'

At that moment, they knew… but still he hadn't said it.

'I'd say the body was in the water not less than eight hours and not more than twenty-four. As to when death occurred, well, some time before that, obviously, but not too long, a matter of hours

'And cause of death?'

Dr Curt smiled. 'The photographs of the skull show a clear fracture to the right-hand side of the head. She was hit very hard from behind, gentlemen. I'd say death was almost instantaneous…"

There was more, but not much more. And much mumbling between officers. Rebus knew what they were thinking and saying: it was the same M.O. as the Dean Bridge killing. But it wasn't. The woman found at Dean Bridge had been murdered at that spot, not transported there, and she had been murdered on a riverside path in the middle of a city, not… well, where had Liz Jack died? Anywhere. It could be anywhere. While people were muttering that William Glass had to be found, Rebus was thinking in a different direction: Mrs Jack's BMW had to be found, and found quickly. Well, he was already packed, and he'd okayed the trip with Lauderdale. Constable Moffat would be there to meet him, and Gregor Jack had provided the keys.

'So there it is, ladies and gentlemen.' Curt was saying. 'Murder would be my opinion. Yes, murder. The rest is down to your forensic scientists and yourselves.'

'Off are you?' Lauderdale commented, seeing Rebus toting his bag.

That's right, sir.'

'Good hunting, Inspector.' Lauderdale paused. 'What's the name of the place again?'

'Where is it expensive to be a Mason, sir?'

'I don't follow… ah, right, a dear lodge.'

Rebus winked at his superior and made his way out towards his car.

It was very pleasing the way Scotland changed every thirty miles or so – changed in landscape, in character, and in dialect. Mind you, stick in a car and you'd hardly guess. The roads all seemed much the same. So did the roadside petrol stations. Even the towns, long, straight main streets with their supermarkets and shoe shops and wool shops and chip shops… even these seemed to blur one into the other. But it was possible to look beyond them; possible, too, to look further into them. A small country, thought Rebus, yet so various. At school, his geography teacher had taught that Scotland could be divided into three distinct regions: Southern Uplands, Lowlands, and Highlands… something like that. Geography didn't begin to tell the story. Well, maybe it did actually. He was heading due north, towards a people very different to those found in the southern cities or the coastal towns.

He stopped in Perth and bought some supplies – apples, chocolate, a half bottle of whisky, chewing gum, a box of dates, a pint of milk… You never knew what might not be available further north. It was all very well on the tourist trail, but if he stepped off that trail…

In Blairgowrie he stopped for fish and chips, which he ate at a Formica-topped table in the chip shop. Lashings of salt, vinegar and brown sauce on the chips. Two slices of white pan bread thinly spread with margarine. And a cup of dark-brown tea. The haddock was covered in batter, which Rebus picked off, eating it first before starting on the fish.