Logan pulled down the collar of his shirt, exposing his neck in all its strangled glory.

Watson winced again, but this time for him. Desperate Doug's finger marks stood out against the pale skin in red and purple. The two biggest bruises sitting on either side of the windpipe, where the old man's thumbs had tried to squeeze the life out of him.

'Jesus, whad happened?'

'I kind of fell down and couldn't get up.' Logan went back to rubbing his throat. 'Mr MacDuff wanted to make it permanent.' The knife blade flashing in the light. He shivered again.

'The old bastard!'

Logan almost smiled; it was nice to have someone on his side for a change. DI Insch was not so understanding. When they got back to Force Headquarters, Logan with another pocket full of painkillers and WPC Watson with confirmation that her nose wasn't broken, the message was delivered by the desk sergeant: Logan was to report to the inspector's office. Now!

The inspector was standing with his back to the door, hands clasped behind his back, his bald head shining in the overhead lighting as Logan entered. Insch was staring out of the window at the steadily falling snow. 'What the hell did you think you were doing?' he asked.

Logan rubbed at his throat again and said he was trying to arrest George Stephenson's killer.

Insch sighed. 'Sergeant, you just beat an old man unconscious. The hospital say his condition is serious. What if he dies? Can you imagine how that's going to play in tomorrow's paper? "Policeman Beats Pensioner To Death!" What the hell were you thinking?'

Logan cleared his throat and wished he hadn't. It hurt. 'I…I was defending myself.'

Insch spun around, his face beetroot-red. 'Reasonable force does not include battering old…' He stopped when he saw Logan's bruise-ringed neck. 'What happened? Watson go into a love-bite feeding-frenzy?'

'Mr MacDuff tried to strangle me. Sir.'

'That why you hit him?'

Logan nodded, wincing. 'It was the only way to make him stop.' He dug a clear plastic wallet out of his pocket and clunked it down on DI Insch's desk with a trembling hand. There was a Stanley knife inside. 'He was going to carve me up with that.'

Insch picked up the knife, twisting it around, examining it through the plastic. 'Nice to see the old ways aren't dying out,' he said at last before looking Logan square in the eye. 'You're probably going to be suspended from duty while this is investigated. If Desperate Doug decides to press charges…' he shrugged. 'You know what it's like around here right now. We don't need any more bad PR.'

'He was going to kill me…'

'You beat an OAP unconscious, Logan. It doesn't matter why. That's all they're going to see. Police brutality of the worst kind.'

Logan couldn't believe his ears. 'So you're hanging me out to dry?'

'Sergeant, I'm not doing anything. Professional Standards won't let me. This is all out of my hands.' The incident room was empty except for Logan and his paperwork. He sat in the semidarkness, a cup of cold coffee on the table next to a half-eaten packet of Maltesers. Trying not to shake.

The knife.

Logan ran a hand over his face. He'd not thought about that night for a long time. Lying on the tower block roof, half-unconscious, while Angus Robertson stabbed and stabbed and stabbed…Desperate Doug MacDuff had brought it all screaming back.

Logan had filled in all the forms, explaining why he'd put an old age pensioner in the hospital. Had spent a happy hour and a half while Inspector Napier scowled at him, asked leading questions and left him in no doubt about what was going to happen next. Now there was nothing left to do but sit back and wait to be told he was suspended. One week back on the job and already his career was down the tubes. And it wasn't even his fault!

Sighing, he looked up at Geordie Stephenson's dead face. Worst of all Desperate Doug was going to be that much harder to convict now. The jury would see a poor old man, beaten by the police, fitted up for the murder of an Edinburgh hoodlum. How could that old man murder anyone? He was so frail! The Procurator Fiscal wouldn't touch it with a bargepole.

Logan let his head sink forward until it clunked off the pile of papers. 'Shit.' He banged his forehead on the table, in time with the words: 'Shit, shit, shit, shit…'

He was interrupted by the blaring tune from his mobile phone. Sighing, he pulled the thing out, and stuck it to his ear. 'Logan,' he said, without enthusiasm.

'DS McRae? This is Alice Kelly, we met yesterday? At the safe house? We were looking after Mr Philips?'

Logan had the sudden image of a frumpy, plain-clothes policewoman with too many rings. 'Hello…' He stopped and sat up. 'What do you mean: you "were" looking after him? Where is he?'

'Ah, yes. You see that's the thing.' Embarrassed pause. 'DC Harris went out to the shops for a pint of milk and some crisps while I was in the shower-'

'Don't tell me you've lost him!'

'We didn't really lose him. I'm sure he's just gone out for a walk. He'll be back as soon as it gets dark…'

Logan looked at his watch. It was three-thirty. It was already dark. 'Have you looked for him?'

'DC Harris's out there now. I'm staying here, in case he comes back.'

Logan banged his head off the table again.

'Hello? Hello? Is something wrong?'

'He's not coming back.' The words came out through gritted teeth. 'Have you told Control he's missing?'

Another embarrassed pause.

'Oh for God's sake,' said Logan. 'I'll let them know.'

'What do you want me to do?'

Logan was a gentleman and didn't tell her.

Ten minutes later every patrol car in Aberdeen knew to keep an eye out for Roadkill wandering the streets. Not that Logan needed psychic powers to know where he would be going. He'd be making for the farm and its buildings full of dead things.

It was a fair walk to Cults from Summerhill, especially in the driving snow, but Roadkill was used to long walks. Pushing his own portable morgue along the highways and byways of the city. Collecting dead animals along the way.

But Bernard Duncan Philips didn't get that far. He was found three and a half hours later, lying in a pool of slowly freezing blood, in Hazlehead Woods. The woods were fairytale black and white, old twisted trees frosted with ice, blanketed in snow. A single-track road twisted its way through the centre of the park and Logan crept his pool car along it, keeping the speed down trying to keep the thing from sliding off the road and into a tree.

A mile and a half into the woods there was a rough car park, no tarmac, just dirt compacted over years and years of use, hidden beneath the snow. A single, large beech tree sat in the middle, bedecked in winter and surrounded by policemen milling about with no real obvious purpose, breath pluming out into the bitter air. Freezing their nuts off.

Logan pulled up next to the grubby IB van, killed the engine and clambered out into the slippery, hard-packed snow. The cold air was like a slap in the face. He shivered his way to the crime scene tent, hoping to God it would be warmer inside. It wasn't. Blood was spattered out from the middle of the tent, where a big pool of dark red was thickening with ice crystals, making the surface glitter. There were footprints everywhere and a man-shaped depression, straddling the pool of blood. Roadkill had been lying on his side. Bleeding his life out into the snow.

Logan grabbed the photographer. It was Billy: the balding AFC fan who'd taken photos at the tip. He was still wearing the same red-and-white bobble hat.

'Where's the body?'

'A amp;-E.'

'What?'

'He's no dead.' The photographer looked down at the crimson stain and then at Logan. 'No yet anyway.'

Which was how Logan ended up back at Aberdeen Royal Infirmary for the second time that day. Bernard Duncan Philips had been admitted with a fractured skull, broken ribs, broken arms, one broken leg, fractured fingers and internal injuries consistent with someone repeatedly stamping on his stomach. He'd been taken straight into surgery, but the mob had done a thorough job this time. Roadkill wasn't expected to survive.