'I need to get a vehicle check on one Darren Caldwell,' he said, doing a quick bout of mental arithmetic. Darren had knocked up Miss Erskine when she was fifteen, plus nine months for gestation, plus five years for the kid's age. Presuming they were in the same class when their 'eternal love' turned physical Darren had to be twenty-one – twenty-two by now. Give or take a few months. 'He's in his early twenties and allegedly living in Dundee…' He nodded as the officer on the other end of the phone recited the details back to him. 'Yeah, that's right. How quick can you get that for me? OK, OK, I'll hold.'

The press officer was standing in front of him, looking as if someone had dropped a live herring down her pants. 'The press are all over us!' she wailed while Logan held on for his vehicle check. 'That bloody Hissing Sandy Lawyer Bastard is calling us every shade of shite under the sun!' Her face was florid, the beetroot tinge extending from her blonde fringe all the way down her neck like sunburn. 'Do we have anything to tell them? Anything at all? Anything that makes us look like we're getting somewhere?'

Logan put one hand over the mouthpiece and told her they were pursuing several lines of enquiry.

'Don't give me that!' She almost exploded. 'That's the shite I give them when we haven't got a bloody clue! I can't tell them that!'

'Look,' he said, 'I can't just conjure arrests out of thin…Hello?'

The voice on the phone was back: 'Aye, I've got fifteen Darren Caldwells in the north-east. Mind, only one of them lives in Dundee and he's in his late thirties.'

Logan swore.

'But I've got one Darren Caldwell, twenty-one, livin' in Portlethen.'

'Portlethen?' It was a little town about five miles south of Aberdeen.

'Aye. Drives a dark red Renault Clio. You want the registration number?'

Logan said he did, closed his eyes and thanked God something was starting to go his way. A witness had seen a child matching Richard Erskine's description getting into the back of a dark red hatchback. He copied down the registration number and address, thanked the man on the other end of the phone and beamed at the agitated press officer.

'What? What? What have you got?' she demanded.

'We're hoping an arrest will be imminent.'

'What arrest? Who are you arresting?'

But Logan was already gone.

14

The PC he'd grabbed from the locker room sat behind the wheel of the CID pool car, breaking the speed limit, heading south. Logan sat in the passenger seat, watching the dark countryside whip past the window. Another PC and a WPC sat in the back. Traffic was light at this time of night and it wasn't long before they were drifting slowly past the address Logan had been given for Darren Caldwell.

It was a new-looking bungalow on the south side of Portlethen, part of a winding development of identical, new-looking bungalows. The front garden was little more than a few square feet of grass, bordered with wilted roses. Some limp red petals still clung to the flower heads: the rain had battered off the rest. They lay in a soggy heap at the base of the bushes, turning a sickly shade of brown in the streetlights.

Sitting in the small lock-block drive was a dark red Renault Clio.

Logan got the driver to park around the corner. 'OK,' he told the PCs, unbuckling his seatbelt, 'we're going to take this nice and easy. You two work your way round the back. Let me know when you're in place and we'll ring the doorbell. If he runs: you grab him.' He turned to the WPC in the back, wincing as the movement pulled at the scars on his stomach. 'When we get to the house I need you to keep out of sight. If Caldwell sees police on his doorstep he's going to freak. I don't want this turning into a siege. OK?'

Everyone nodded.

It was freezing cold as Logan climbed out of the car. The rain had changed from thick, heavy drops back into a fine, icy drizzle that leached all the warmth out of his hands and face by the time they reached the front door. The two PCs had disappeared around the back.

A couple of lights were on in the house, the sound of a television seeping out from the lounge. A toilet flushed and Logan reached for the doorbell.

The phone blared in Logan's pocket. He cursed quietly and punched the pickup. 'Logan.'

'What's going on?' It was Insch.

'Can I call you back, sir?' he whispered.

'No you bloody well can't! I just got a call from HQ. They tell me you've commandeered three uniforms and are off arresting someone! What the hell is going on?' There were some muffled noises from the earpiece and the sound of a band striking up. 'Shite,' said Insch. 'I'm on. You better have a damn good explanation when I get off stage, Sergeant, or I'll A woman's voice, terse and insistent, just too faint for Logan to make out the words, and then: 'All right, all right. I'm coming.' And then the line went dead.

The WPC stood on the doorstep looking at him with her eyebrows arched.

'He's about to go on stage,' explained Logan, stuffing the phone back in his pocket. 'Let's get this over and done with. If we're lucky we can meet him in the bar after the show with some good news for a change.'

He rang the bell.

A thin bout of male swearing drifted out of the bathroom window. At least they knew someone was home. Logan leaned on the bell again.

'Hold on! Hold on, I'm coming!'

About a minute and a half later a shadow fell over the part-glazed front door and a key was rattled in the lock. The door swung open and a face popped into the gap.

'Hello?' it said.

'Darren?' asked Logan.

The face frowned, a pair of thick black eyebrows sinking down over eyes that didn't quite look in the same direction. Darren Caldwell might be five and a bit years older than his school photograph, but he hadn't changed that much. His jaw was a little wider and his hair looked styled, rather than cut by his mum, but it was definitely the same man.

'Yes?' said Darren, and Logan gave the door a sudden shove.

The young man staggered backwards, tripped over a little nest of tables and fell full length on the floor. Logan and the WPC stepped inside, closing the door behind them.

'Tsk, tsk.' Logan shook his head. 'You should get a security chain fitted, Mr Caldwell. Makes it harder for people to come in uninvited. You never know who's out there.'

The young man scrabbled to his feet, balling his fists. 'Who are you?'

'You have a lovely home, Mr Caldwell,' said Logan, letting the WPC get between him and the possibility of physical violence. 'You don't mind if we take a look around?'

'You can't do this!'

'Oh yes I can.' Logan pulled the search warrant out and waved it in his face. 'Now where shall we start?'

The house was a lot smaller on the inside than it looked. Two bedrooms, one with a double bed covered in a yellowy-grey crocheted blanket crammed into it, jars of moisturiser cluttering up the vanity unit; the other with a single bed up against one wall opposite a little computer desk. A barely-dressed young woman pouted from a poster above the bed. Very saucy. The bathroom contained the nastiest avocado-coloured suite Logan had seen in a long time and the kitchen was just big enough for all three of them to stand in, as long as they didn't move about too much. The lounge was taken up by a widescreen television and a huge, lime-green sofa.

There was no sign of the missing five-year-old boy.

'Where is he?' asked Logan, poking about in the cupboards, pulling out tins of beans and soup and tuna.

Darren looked left and right, almost at the same time. 'Where's who?' he said at last.

Logan sighed and slammed the cupboard doors.

'You know bloody well "who", Darren. Where's Richard Erskine. Your son? What have you done with him?'