The personnel behind the front desk at the police station didn’t know him, so he pulled out his badge. ‘I’m Carl Mørck. Hi. My mobile is dead. Can I use your telephone?’

One of the cops pointed at an old contraption behind the desk while trying to console a young girl who’d wandered away from her big sister. Ages ago Carl had been the cop on the beat, consoling children. It was actually sad to think about.

Just as he was about to dial the number, he spotted Assad through the blinds. He was standing next to the stairwell to the public lavatories, half hidden behind a flock of excited high-school students wearing rucksacks. He didn’t look too good, scoping out the territory in his wretched coat.

‘Thanks for letting me use the phone,’ Carl said, and hung up.

Only five or six yards separated them by the time Carl was outside the police office and about to hail Assad, when someone came from behind Assad and grabbed his shoulder. He was dark-skinned, about thirty years old, and didn’t seem particularly friendly. In one jerk he spun Assad round and began shouting curses at him. Carl didn’t understand what he was saying, but Assad’s expression left no doubt. Friends they weren’t.

A couple of the girls among the flock of students looked at them indignantly. Lowlife! Tossers! their faces seemed to say through arrogant masks.

Then the man lashed out at Assad, and Assad struck back with an incredibly precise and devastating blow that stopped the man in his tracks. For a moment he stood wobbling, as the schoolteachers discussed whether or not to get involved.

But Assad didn’t care. He grabbed the man roughly and clutched him tight, until he began shouting again.

Then, as the school group angled away from the scene, Assad caught sight of Carl, and his reaction was instantaneous. He shoved the man away and gave him a hand gesture that invited him to fuck off. Before the man reached the stairway to the train platform, Carl managed to get a glance at him. At his razor-sharp sideburns and glistening hair. He was a handsome guy with a hateful gaze. Not the kind of man one wished to see again.

‘What just happened?’ Carl asked.

Assad shrugged. ‘I’m sorry, Carl. He’s just some idiot.’

Assad’s eyes roamed all over. Towards the police station behind Carl, towards the schoolchildren, towards Carl, and beyond. This was a completely different Assad to the one who made mint tea in the basement. A man with a score to settle.

‘You’ll tell me what that was all about when you’re ready, OK?’

‘It was nothing. Just a neighbour of mine.’ Then he smiled. Not convincingly, but almost. ‘You got my message then? You know your mobile is completely dead, right?’

Carl nodded. ‘How do you know it was Kimmie you saw?’

‘A junkie prostitute called out her name.’

‘Where is she now?’

‘I don’t know. She managed to get away in a taxi.’

‘Bloody hell, Assad. You followed her, didn’t you?’

‘Yes. My taxi was right behind hers, but when we reached Gasværksvej, her taxi had stopped just around the corner. She was already gone then. I was just a second too late, and she was gone.’

Success and failure, all at once.

‘Her taxi driver said that she’d given him five hundred kroner. She’d just hopped in the back seat, shouting, “Drive to Gasværksvej! Fast. The money’s all yours.” ’

Five hundred kroner for five hundred yards. That’s desperation.

‘I searched for her, of course. Went in all the shops to hear if they’d seen anything. Rang doorbells.’

‘Did you get the taxi driver’s number?’

‘Yes.’

‘Bring him in for questioning. There’s something fishy about this.’

Assad nodded. ‘I know who the junkie prostitute is. I have her address.’ He handed him a note. ‘I got it from this police station ten minutes ago. Her name is Tine Karlsen. She has a bedsit down on Gammel Kongevej.’

‘Well done, Assad. But how did you get the information from the officers? Who did you say you were?’

‘I showed them my ID from headquarters.’

‘That doesn’t allow you to get that kind of information, Assad. You’re a civil employee.’

‘Well, I got it anyway. But it would be good then if I got a badge now that you’re sending me out so much, Carl.’

‘I’m sorry, Assad, but I can’t do that.’ He shook his head. ‘You said they knew her at the station. Has she been arrested?’

‘Oh, yes. Many times. They are rather tired of her. She usually goes around begging for money near the train station’s main entrance.’

Carl looked up at the yellow building buttressed against Teaterpassagen. Lots of sets of rooms on the lower four floors, attic rooms at the top. It wasn’t difficult to guess where Tine Karlsen lived.

The door to the fifth floor was opened by a gruff-looking man in a threadbare blue dressing gown. ‘Tine Karlsen, you say? Follow me.’ He led Carl past the stairwell and into a corridor with four or five doors. He pointed at one as he clawed his grey beard. ‘We don’t like having the police running around up here,’ he said. ‘What did she do?’

Carl squinted, drawing one of his acerbic smiles from his goody bag. The man earned wads of cash on these small, crappy rooms. So he could bloody well treat his tenants properly.

‘She’s an important witness in a renowned case. I request that you give her the support she needs. Do you understand?’

The man let go of his beard. Did he understand? He had absolutely no idea what Carl was talking about. But it didn’t matter – so long as it worked.

She didn’t open her door until he’d pounded on it for what seemed an eternity. Her face was extraordinarily ravaged.

Inside the room he was met with a pungent, nasty odour, the smell a pet’s cage exudes when it isn’t cleaned often enough. Carl remembered all too well that phase of his stepson’s life – when his hamsters mated day and night on his desk. In no time the number had multiplied fourfold, and that trend would have continued if the boy hadn’t lost interest and the animals hadn’t begun eating each other. In the months before Carl donated the rest of the critters to a day-care centre, the stink was a permanent fixture of the home atmosphere.

‘You’ve got a rat, I see,’ he said, bending towards the little monster.

‘His name’s Lasso and he’s completely tame. Would you like me to take it out so you can hold it?’

He tried to smile. Hold it? A mini-pig with a hairless tail? He’d sooner eat its fodder.

It was at that point Carl decided to show her his police badge.

She glanced disinterestedly at it and wobbled over to the table. With an experienced hand, she pushed a syringe and some tinfoil fairly discreetly under a magazine. Heroin, if he were to venture a guess.

‘I understand you know Kimmie?’

Had she been arrested with a needle in her veins or shoplifting or jerking off a customer on the street she wouldn’t have batted an eye. But that question made her jump.

Carl moved to the dormer window and looked out over the soon-to-be barren trees that ringed St Jørgen’s Lake. Hell of a nice view this junkie had.

‘Is she one of your best friends, Tine? I’ve heard you two are close.’

He leaned right up against the window and gazed down at the footpath alongside the water. Had the girl been normal, she might be jogging around the lake a few times a week like the ones doing so now.

His eyes scanned the bus stop on Gammel Kongevej, where a man in a light-coloured coat stood staring up at the building. Carl had seen the guy from time to time during his many years on the force. Finn Aalbæk. A gaunt ghost of a man who used to camp at Antonigade Police Station so his little detective agency could sponge bits of information from Carl and his colleagues. It had been at least five years since Carl had last seen him, and he was still just as ugly.

‘Do you know the man in the light-coloured coat down there?’ he asked. ‘Have you seen him before?’