‘Sure.’

‘And there is a pile of mail by the front door. That should tell us when he was last here. And try to talk to the tenant in the other flat, find out when they last saw him.’

‘All right.’

‘Forensics should be here soon. I know they don’t like being told what to do, but there are a couple of dressing gowns on the bedroom door. And there are condoms in the bedside table. They should check the sheets.’

‘I’ll nudge them.’

DC Sophie Byrne went with Hussein in the car and guided her through some of the printouts as they drove along by St James’s Park. Hussein felt like one of those people you saw going into an exam still desperately trying to do the revision they should have done earlier. She’d never been one of those people. It made her uncomfortable. She liked being prepared.

She was expected. A uniformed officer escorted her through security and into a lift, then up to a floor that needed a card to access it. There, she was introduced to a receptionist who took her through into the commissioner’s office; her first impression was of a blaze of light and that she hadn’t realized how high up she was. She felt a childish urge to run to the window and enjoy the view over the park.

Looking at Crawford, she was struck by several impressions at the same time. His smiling florid face. His uniform. The size of his desk. And its emptiness, except for a single file. Didn’t he have papers to sign? Or was he too important even for that?

‘Detective Chief Inspector Hussein,’ said Crawford, as if he were savouring each word individually. ‘It’s taken too long for us to meet.’

‘Well …’ Hussein began, then couldn’t think of anything to add.

‘We’re proud to have a senior officer from your community.’

‘Thank you, sir.’

‘Where do you come from, Sarah? Originally.’

‘Birmingham, sir.’

There was a pause. Hussein looked out of the window. The sun was shining. She suddenly felt how nice it would be to be out there, walking in the park on a summer evening, rather than here.

‘This case,’ said Crawford. ‘Alexander Holland. Tell me about it.’ He waved her into a chair in front of his desk.

She told him about the discovery of the body and its state, and about his flat.

‘And you met Frieda Klein?’

‘Briefly.’

‘What do you think about her?’

‘She was the one who identified the body. Holland had her hospital identification tag on his wrist.’

‘That sounds a bit odd.’

‘They’d been a couple.’

‘I mean, I’ve heard of wearing someone’s ring but …’

‘I’d planned to talk to her again.’

‘What do you actually know about her?’

‘Just what one of my DCs told me on the way over. The name rang a bell but I couldn’t place it. I gather she was the therapist who was involved in getting that Faraday boy back a few years ago and with that murder down in Deptford. There was that other one. The tabloids called it “The Croydon House of Horrors”. That was her too.’

‘You shouldn’t believe everything you read in the papers.’

‘I’m just going by what was in the police files. Wasn’t she involved?’

Crawford gave a sort of snort. ‘There’s involved and involved,’ he said.

‘I don’t understand.’

‘You know how it is,’ he said. ‘When we get a result suddenly everybody wants to jump on the bandwagon. And the papers love it, the idea of a bloody therapist coming in here and telling us how to do our job.’

‘The only thing I read about her in the papers, she was being blamed for something. I can’t remember what it was.’

‘You don’t know the half of it,’ said Crawford, darkly.

There was another pause.

‘I’m sorry,’ said Hussein, who was feeling irritated now. ‘I’m probably being slow, but I’m not clear what you’re telling me.’

Crawford leaned forward and, with the tips of the fingers of his right hand, pushed the file across the desk. ‘That’s the other file on Frieda Klein,’ he said. ‘That’s my file. You can take it away with you.’ He stood up and walked to the window. ‘But I’ll give you the short version.’ He looked around, and when Hussein saw his face, it was as if someone had turned a dial to make him angrier. ‘I’ll tell you, Sarah … Is it all right if I call you Sarah?’

‘Of course, sir.’

‘When someone called me and said that a body had been found and that Frieda Klein was involved, I told myself that this time I was going to find out who was in charge and I was going to warn them in advance. You’ve already met Klein and you probably saw her as some quiet, studious doctor type …’

‘I didn’t really –’

‘But she isn’t. You say you read about her in the papers.’ He stepped forward and rapped on the desk. ‘I’ll tell you what wasn’t in the papers. Did you know that she killed a woman?’

‘Killed?’

‘Stabbed her to death. Cut her throat.’

‘Was she charged?’

‘No, it was considered to be self-defence. Klein didn’t even admit to that. She said it was done by Dean Reeve, the kidnapper in the Faraday case.’

Hussein frowned. ‘Dean Reeve? But he died. He hanged himself before the police could get him.’

‘Exactly. But this is Frieda Klein we’re talking about. She operates under different rules from the rest of us. She has this bee in her bonnet that Dean Reeve is still alive and it was his identical twin who died. Ridiculous, of course. Also, everyone talks about Klein getting that Faraday boy back and the girl. They don’t mention the other woman Klein got involved and didn’t get rescued.’

‘How did Klein get her involved?’

‘What?’ Crawford seemed at a loss for a moment. ‘I can’t remember the details. It’s all in the files. She’s been arrested for assault as well. She got into a brawl in a West End restaurant a few years ago.’

‘Was she convicted?’

‘Charges were not pressed,’ said Crawford, ‘for reasons that were never clear to me.’ He tapped the file. ‘But it’s all in here.’

‘Is she still on the payroll?’

‘God, no. I saw to that. The last I heard she was up in Suffolk crying rape, hurling accusations around, and the man she accused also ended up being murdered. That’s what I’m trying to tell you, Sarah. Wherever this woman goes, trouble follows and people get killed. The only blessing about the last sorry business is that she was up in Suffolk, annoying the police there, rather than down here annoying us.’

‘Rape?’ said Hussein. ‘Was she a victim or investigating a rape or what?’

‘A bit of both, as far as I could gather. It ended up with two people being murdered, as it generally seems to when Dr Klein is involved.’

Hussein reached out her hand towards the file and took it. ‘I’m sorry,’ she said. ‘I want to be clear about this. What is it that we’re talking about here? Are you claiming that this woman is delusional or are you accusing her of something systematic or do you have certain suspicions or … well, what?’

‘You’ll be wanting to talk to people, I’m sure, in the course of the investigation. I’m going to put you in touch with a psychological expert that we really do employ, Hal Bradshaw. He shared my reservations about her performance, had something of a run-in with her and his house ended up being burned to the ground. About which, I have to say, he has been remarkably forgiving.’

‘Are you suggesting that Frieda Klein is an arsonist as well?’

Crawford spread his hands in a gesture of helpless innocence. ‘I’m suggesting nothing,’ he said. ‘I’m a simple policeman. I just follow where the evidence leads me, and in this case the evidence suggests that where Frieda Klein goes a trail of chaos follows. What her precise role in this happens to be has always been difficult to pin down. As you will probably discover, Frieda Klein also has some strange associates. How these things happen, I don’t pretend to know, but they happen, and they continue to happen.’

‘But when she did work with the force,’ said Hussein, ‘to the extent that she did, who did she deal with?’