'-little naked boys,' Insch finished for him. 'Bastard. Get an APB out. I want Strichen and I want him now!' They had the lights and sirens going all the way from Duthie Park to Middlefield, only switching them off as they got within earshot of Martin Strichen's house. They didn't want to scare him off.

25 Howesbank Avenue was a middle terrace house in a sweeping street on the north-west corner of Middlefield. There was nothing behind the row of white-harled buildings except a small belt of scrubby grassland and then the disused granite quarries. After that it was a steep climb down to Bucksburn with its paper mills and chicken factory.

The wind was howling along the back of the houses, kicking up a curtain of snow from the frozen ground to mix with the fresh, icy flakes falling from above. It clung to the building's walls as if someone had wrapped them in glittering cotton wool. Christmas trees sparkled and flashed in the darkened windows; jolly Santas stuck to the glass. And here and there someone had tried to recreate old-fashioned leaded windows with black electrical tape and spray-on snow. Classy.

Watson pulled the car up around the corner from the house, where it couldn't be seen.

Insch, Watson, Logan, and a uniformed PC Logan still thought of as the Bastard Simon Rennie, all clambered out into the snow. It had taken the Fiscal exactly three minutes to approve an apprehension warrant for Martin Strichen.

'Right,' said Insch, looking up at the house. It was the only one on the street that didn't have a Christmas tree merrily sparkling away in the front window. 'Watson, Rennie: you go round the back. No one in, no one out. Give us a bell when you get there.' He held up his mobile phone. 'We'll take the front.'

The uniformed contingent hunkered down into the ripping, ice-laden wind and disappeared around the back of the terraced row.

Insch looked at his DS with an appraising eye. 'You going to be up to this?' he asked Logan.

'Sir?'

'If this gets rough: are you up to it? I'm not having you drop down dead on me.'

Logan shook his head, feeling the tips of his ears burn in the bitter gale. 'Don't worry about me, sir,' he said, his breath whipped away by the wind before it could make a cloud of vapour. 'I'll hide behind you.'

'Aye,' said Insch with a smile. 'Just make sure I don't fall on you.'

The phone in the inspector's pocket buzzed discreetly. Watson and Rennie were in place.

Number 25 had a front door that hadn't seen a coat of paint in years. The peeling blue revealing bloated grey wood underneath, sparkling with frost. A pair of rippled glass panes were set into it, revealing a darkened hall.

Insch tried the doorbell. Thirty seconds later he tried the doorbell again. And a third time.

'All right! All right! Hold your bloody horses!' The voice came from deep within the small house, followed by blossoming light that oozed through the glass.

A shadow fell across the hall, bringing with it muttered swearing, not quite low enough to be inaudible.

'Who is it?' It was a woman, and her voice, rough from years of booze and fags, had all the welcome of a rabid Rottweiler.

'Police.'

There was a pause. 'What's the little bastard done now?' But the door remained shut.

'Open the door please.'

'The little bastard's not here.'

Colour was beginning to travel up DI Insch's neck. 'Open this damn door now!'

Click, clunk, clatter. The door opened a crack. The face that peered out at them was hard and lined, a cigarette dangling out of one corner of the twisted, thin mouth. 'I told you: he's no here. Come back later.'

Insch wasn't having any more of this. Pulling himself up to his full height, he leant his considerable weight on the door and shoved. The woman on the other side staggered back and he stepped over the threshold and into the small hallway.

'You can't come in here without a warrant! I have rights!'

Insch shook his head and marched past her, through a small kitchen, and opened the back door. Watson and Rennie staggered in out of the cold, snow whipping past them into the dingy room.

'Name?' demanded Insch, pointing a fat finger at the outraged woman. She was dressed for the next ice age: thick woollen jumper, thick woollen skirt, heavy woollen socks, big fleecy slippers and, over the top of it all, an extra large cardigan in dung-brown. Her hair looked as if it had been styled in the nineteen fifties and not touched since. It glistened in greasy-looking curls, held tight to her head with hairgrips and an off-brown net.

She crossed her arms, hitching up her sagging bosoms. 'You got a warrant, you tell me.'

'Everyone watches too much bloody television,' muttered Insch, pulling the apprehension warrant out and slapping it in her face. 'Where is he?'

'I don't know.' She scrabbled backwards towards the dingy lounge. 'I'm not his keeper!'

The inspector took a step forward, his face purple, veins standing out on his face and neck. The old woman flinched.

Logan's voice cut through the tension. 'When did you last see him?'

She swivelled her head. 'This morning. Went to do his bloody community service. Little bastard's always doing community service. Dirty little pervert. Can't get a bloody job, can he? To busy playing with himself in bloody changing rooms for that.'

'OK,' said Logan. 'Where was he working today?'

'I don't bloody know, do I? The little bastard calls them in the morning and they tell him where he's supposed to go.'

'Calls where?'

'The council!' She almost spat at him. 'Where else? Number's on the phone table.'

There was an occasional table, not much bigger than a postage stamp, with a grubby cordless phone on it and a small pad marked 'Messages'. A letter was pinned to the mahogany-effect wood by the phone's base unit. It bore the crest of Aberdeen City Council: three towers, bordered by what looked like barbed wire, on a shield supported by a pair of rampant leopards. Very regal. It was Martin Strichen's community service notice from the Parks Department. Pulling out his mobile phone, Logan punched in the number and spoke to the man responsible for handing out Strichen's work details.

'Want to take a guess?' he said when the call was over.

'Duthie Park?' said Insch.

'Bingo.' They dragged details of Martin's car out of his mother while PCs Rennie and Watson searched the house. Watson returned, grim-faced, holding a clear plastic evidence wallet containing a pair of secateurs.

Once Mrs Strichen heard what her little boy had done, she was more than happy to help the police lock him up for life. He deserved it, she said. He'd never been any good. She wished she'd strangled him at birth, or better yet stabbed him in the womb with a coat hanger. God knew she'd drunk enough gin and whisky to kill the little bastard off when she was carrying him.

'Right,' said Insch when she'd stomped off upstairs to the toilet. 'It's highly unlikely he's going to come back here to the loving arms of his delightful mother, not after we get his name and description out to the media. But you never know. Watson, Rennie, I want you to stay here with the Wicked Witch of Middlefield. Keep well clear of the windows: I don't want anyone knowing you're here. If her boy does come home: call for backup. You only tackle him if it's safe.'

Watson looked at him incredulously. 'Come on, sir! He's not coming back! Don't leave me here. PC Rennie's enough to keep an eye on things!'

Rennie rolled his eyes and puffed. 'Thanks a bundle!'

She frowned at him. 'You know what I mean. Sir, I can help, I can-'

Insch cut her off. 'Listen up, Constable,' he said. 'You are one of the most valuable people I have on my team. I have the greatest respect for your professional skills. What I don't have is time to massage your bloody ego. You're staying here to take charge of things. If Strichen does come back I want someone here who can put his lights out.'