Sergey lowered his knife, stood with bowed head, rolled his eyeballs upwards so that he could see himself in the mirror. He looked good: fit, menacing, dangerous, ready. Like a film poster. His tattoo would reveal that he had killed a police officer.

He would stand behind the policeman. Step forward. With his left hand he would grab his hair, pull him backwards. Place the knife tip against his neck, to the left, penetrate the skin, arc the blade across the throat in a crescent shape. Like that.

The heart would pump out a cascade of blood; three heartbeats and the flow would diminish. The man would already be brain-dead.

Fold the knife, slip it into his pocket as he left, fast, but not too fast. Don’t look anyone in the eye. Walk, and feel free.

He stepped back a pace. Stood up straight, inhaled. Visualised the scene. Released his breath. Stepped forward. Angled the blade so that it had a wonderful glint, like a precious jewel.

Beate and Harry came out of Hausmanns gate, turned left, rounded the corner of the block and crossed the site of the burnt building, still with blackened glass shards and scorched bricks in the rubble. Behind it, an overgrown slope ran down to the river. Harry noted there were no doors at the back of Oleg’s block and that, in the absence of any other way out, there was a narrow fire escape descending from the top floor.

‘Who lives in the neighbouring flat?’ Harry asked.

‘No one,’ Beate said. ‘Empty offices. It’s where Anarkisten, a little newspaper that-’

‘I know it. It wasn’t a bad fanzine. The writers of the culture section work on the big papers now. Were the rooms unlocked?’

‘Broken into. Probably been open for a long time.’

Harry watched Beate, who with a resigned air nodded confirmation of what Harry didn’t need to say: someone could have been in Oleg’s flat and escaped unseen. Straws.

They walked down to the path along the Akerselva. Harry established that the river was narrow enough for a boy with a decent throwing arm to lob the gun over to the opposite bank.

‘If you haven’t found the gun yet-’ Harry said.

‘The prosecuting counsel doesn’t need the gun, Harry.’

He nodded. Gunshot residue on his hands. Witnesses who had seen him showing off with the gun. His DNA on the dead boy.

Ahead of them, leaning against a green iron bench, two white boys in grey hoodies saw them, put their heads together and shuffled off down the path.

‘Looks like pushers can still smell the cop in you, Harry.’

‘Mm. Thought it was just Moroccans who sold hash here.’

‘Competition has moved in. Kosovar Albanians, Somalis, Eastern Europeans. Asylum seekers selling the whole spectrum. Speed, methamphetamine, Ecstasy, morphine.’

‘Heroin.’

‘Doubtful. There’s almost no standard heroin to be found in Oslo. Violin is what counts, and you can get that only round Plata. Unless you want to travel to Gothenburg or Copenhagen, where apparently violin has made a recent appearance.’

‘I keep hearing about this violin stuff. What is it?’

‘New synthetic dope. It doesn’t hinder breathing as much as standard heroin, so even if it ruins lives there are fewer overdoses. Extremely addictive. Everyone who tries it wants more. But it’s so expensive not many can afford it.’

‘So they buy other dope instead?’

‘There’s a morphine bonanza.’

‘One step forward, two steps back.’

Beate shook her head. ‘It’s the war on heroin that’s important. And he’s won that one.’

‘Bellman?’

‘So you’ve heard?’

‘Hagen said he’s busted most of the heroin gangs.’

‘The Pakistani gangs. The Vietnamese. Dagbladet called him General Rommel after he smashed a major network of North Africans. The MC gang in Alnabru. They’re all banged up.’

‘The bikers? In my time biker boys sold speed and shot heroin like crazy.’

‘Los Lobos. Hell’s Angels wannabes. We reckon they were one of only two networks dealing in violin. But they were caught in a mass arrest with a subsequent raid in Alnabru. You should have seen the smirk on Bellman’s chops in the papers. He was there when they carried out the operation.’

‘Let’s do some good?’

Beate laughed. Another feature he liked about her: she was enough of a film buff to be on the ball when he quoted semi-good lines from semi-bad films. Harry offered her a cigarette, which she declined. He lit up.

‘Mm. How the hell did Bellman achieve what the Narc Unit wasn’t even close to achieving in all the years I was at HQ?

‘I know you don’t like him, but in fact he’s a good leader. They loved him at Kripos, and they’re pissed off with the Chief of Police for taking him to Police HQ.’

‘Mm.’ Harry inhaled. Felt it pacify his blood’s hunger. Nicotine. A polysyllabic word, like heroin, like violin. ‘So who’s left?’

‘That’s the snag with exterminating pests. You upset a food chain and you don’t know if all you’ve done is make way for something else. Something worse than what you removed…’

‘Any evidence of that?’

Beate shrugged.

‘All of a sudden we’re not getting any info off the streets. Our informers don’t know anything. Or they’re keeping shtum. There are just whispers about the man from Dubai. No one has seen him, no one knows his name, he’s a kind of invisible puppeteer. We can see violin is being sold, but we can’t trace it back to its source. The pushers we nab say they’ve bought off other sellers at the same level. It’s not normal for tracks to be covered so well. And that tells us this is a simple, very professional outfit controlling import and distribution.’

‘The man from Dubai. The mysterious mastermind. Haven’t we heard that story before? And then he turns out to be a run-of-the-mill crook.’

‘This is different, Harry. There were a number of drugs-related murders over the new year. A type of brutality we haven’t seen before. And no one says a word. Two Vietnamese dealers are found hanging upside down from a beam in the flat where they worked. Drowned. Each one had a plastic bag filled with water on his head.’

‘That’s not an Arab method, it’s Russian.’

‘Sorry?’

‘They hang them upside down, put a plastic bag over their heads and tie it loosely, around the neck. Then they begin to pour water down their heels. It follows the body down to the bag and fills it up. The method’s called the Man on the Moon.’

‘How do you know that?’

Harry shrugged. ‘There was a wealthy surgeon called Birayev. In the eighties he got his hands on one of the original astronaut suits from Apollo 11. Two million dollars on the black market. Anyone who tried to pull a fast one on Birayev or didn’t pay a debt was put in the suit. They filmed the face of the poor guy as they poured in the water. Afterwards the film was sent round to other debtors.’

Harry blew smoke towards the ceiling.

Beate sent him a lingering look and slowly shook her head. ‘What have you been doing in Hong Kong, Harry?’

‘You asked me that on the phone.’

‘And you didn’t answer.’

‘Exactly. Hagen said he could give me another case instead of this one. Mentioned something about an undercover guy who was killed.’

‘Yes,’ Beate said, sounding relieved that they were no longer talking about the Gusto case and Oleg.

‘What was that about?’

‘A young undercover Narc agent. He was washed ashore where the Opera House slopes into the water. Tourists, children, and so on. Big hullabaloo.’

‘Shot?’

‘Drowned.’

‘And how do you know it was murder?’

‘No external injuries; in fact, it looked as if he might have fallen into the sea by accident — his beat was the area around the Opera House. But then Bjorn Holm checked his lungs. Turned out it was fresh water. And Oslo fjord is salt water as you know. Looks like someone chucked him in the sea to make it look as if he had drowned there.’