'No idea. But the old witch makes him sound like Hitler, only without the winning personality.'

'Sounds lovely.'

Inside the Erskine household the only thing that had changed was the air quality. The walls were still lined with those freaky mother-and-son snaps, the wallpaper was still revolting, but the air was thick with cigarette smoke.

In the lounge, Mrs Erskine was weaving away on the couch, unable to sit still, or upright. A large cut-glass tumbler of clear spirit was clutched in her hands, a half-smoked fag between her lips. The bottle of vodka on the coffee table was well on its way.

Her friend, the next-door neighbour, the one who didn't make tea for the police, was perched in an armchair, craning her long, wrinkly neck to see who the newcomer was. Her beady eyes sparkled as soon as she recognized him. Probably hoping that this was going to be bad news. Nothing like someone else's suffering to make you feel good about yourself.

Logan plonked himself down on the couch next to Mrs Erskine. She looked around at him blearily, and an inch of fag ash tumbled down the front of her cardigan.

'He's dead isn't he? My little Richard is dead?' Her eyes were bloodshot from too much crying and too much vodka, her face creased and florid. She looked as if she'd aged ten years in the last ten hours.

The neighbour leaned forward eagerly, waiting for the moment of truth.

'We don't know that,' said Logan. 'I just need to ask you a couple more questions, OK?'

Mrs Erskine nodded and dragged in another lungful of nicotine and tar.

'It's about Richard's father.'

She stiffened as if someone had run a thousand volts through her. 'He hasn't got a father!'

'Bastard wouldn't marry her,' said the neighbour with obvious relish. This wasn't as good as the kid being dead, but dragging up the painful past was a reasonable substitute. 'Got her up the stick when she was just fifteen and then wouldn't marry her. He was a shite!'

'Yes.' The unmarried Mrs Erskine waved the rapidly emptying glass of vodka in salute. 'He was a shite!'

'Course,' the neighbour went on, her voice a theatrical whisper, 'he still wants to see the child. Can you imagine that? Doesn't want to make the kid legal, but he still wants to take him to Duthie Park and play bloody football!' She leaned over and sloshed another huge shot of vodka into her friend's glass. 'There ought to be a bloody law.'

Logan's head snapped up. 'What do you mean, "he still wants to see the child"?'

'I don't let him anywhere near my little soldier.' Miss Erskine raised the tumbler unsteadily to her lips and swallowed about half in one go. 'Oh, he sends little presents and cards and letters, but I throw them all straight in the bin.'

'You told us the father was dead.'

Miss Erskine looked at him, puzzled. 'No I didn't.'

'Might as well be bloody dead. The amount of bloody good he is.' The neighbour said with a smug flourish. And suddenly Logan got a much better picture of what had happened. WPC Watson had told him the father was dead because that's what the rancid old bitch of a neighbour had told her.

'I see,' said Logan slowly, trying to keep his voice neutral. 'And has the father been informed that Richard's gone missing?' It was the second time he'd asked that question in the space of an hour. He already knew the answer.

'It's none of his bloody business!' shouted the neighbour, getting as much venom into her voice as she could. 'He gave up all his bloody rights when he wouldn't make his bloody child legal. Imagine leaving that poor boy to go through life as a bastard! Anyway, the little shit must know by now-' she pointed at an open copy of the Sun lying on the carpet. The headline screamed: 'PAEDOPHILE SICKO STRIKES AGAIN!'

Logan closed his eyes and took a deep breath. The bitter old battleaxe was getting on his nerves. 'You need to tell me Richard's father's name, Mrs…Miss Erskine.'

'I don't see why!' The neighbour leapt to her feet. Now she was playing the noble defender, protecting the poor pissed cow on the sofa. 'It's none of his bloody business what's going on!'

Logan turned on her. 'Sit down and shut up!'

She stood there, mouth agape. 'You…you can't talk to me like that!'

'If you don't sit down and button it, I'm going to have the nice constable here take you down to the station and charge you with giving a false statement. Understand?'

She sat down and buttoned it.

'Miss Erskine: I need to know.'

Richard's mother finished her drink and got unsteadily to her feet. She lurched once to the left and then staggered off in the opposite direction: to the sideboard, where she proceeded to rummage about in a low cupboard shelf, scattering bits of paper and small boxes over the floor.

'Here!' she said triumphantly, holding a deckle-edged cardboard folder with gold ribbons embossed on the side. Just the sort of thing they used to give you when you got your photograph taken at school. She almost threw it at Logan.

Inside was a boy, maybe a little over fourteen. He had a huge pair of eyebrows and a slight squint, but the resemblance to the missing five-year-old was unmistakable. In the corner of the picture, over the mottled blue-and-grey photographer's background, were the words: 'To My Darling Elisabeth, I Will Love You For All Eternity, Darren XXX' written in a child's artificially neat handwriting. Pretty heady sentiments for someone just clearing puberty.

'He was your childhood sweetheart?' asked Logan, turning the brown photo-folder over in his hands. There was a golden sticker with the photographer's name, address and telephone number and another, white paper, spelling out 'DARREN CALDWELL: THIRD YEAR, FERRYHILL ACADEMY'.

'He was a bastard!' said the friend again, relishing every syllable.

'Do you know where he lives?'

'Last I heard he'd upped sticks and moved to Dundee of all places! Dundee!' The friend stuck another fag in her mouth and lit it. She sucked air through it, making the tip glow fiery-red before hissing the smoke out of her nose. 'Little bastard can't wait to get away, can he? I mean here's his kid, growing up without a father and he buggers off to Dundee first chance he gets!' She took another deep drag. 'Ought to be a bloody law.'

Logan didn't point out that, since Darren Caldwell wasn't allowed to see his son, it made no difference where he stayed. Instead he asked Miss Erskine if he could keep the photograph.

'Burn it for all I care,' was all she said.

Logan let himself out.

It was still chucking it down outside and the foosty-looking BMW was still parked where it had a good view of the front of the house. Keeping his head covered, Logan sprinted for the pool car. Cranking the heating up, he set the blowers on full and made his way back to Force Headquarters.

Outside the big concrete-and-glass building there was a knot of television cameras, most of them sporting a serious broadcast journalist looking seriously into the camera and making serious statements about the quality of Grampian Police. The WPC he'd spoken to hadn't been kidding: Sandy the Snake had really whipped up a storm.

Logan tucked the CID car into the car park around the back, steering well clear of the reception area on his way to the incident room.

The room was a flurry of activity again. But this time the whirlwind was centred around a harassed-looking press officer who was standing, clutching a clipboard to her chest, trying to get details out of the four officers on duty while every phone in the place went off. As soon as she clapped eyes on Logan her face lit up. Here was someone to share the stress.

'Sergeant-' she started, but Logan held up a hand and grabbed one of the few silent phones.

'Just a minute,' he said, dialling the records office.

The phone was picked up almost immediately.