‘How tall would the attacker have been?’ Hignett asked.

‘I can’t be exact…’

‘Be inexact.’

‘From the angle at which the blade passed through the windpipe, I’d say he’d be about the same size as Allen. Around six feet.’

Hignett looked towards his team.

‘Luke is five feet ten,’ Porter said.

Hendricks glanced towards Brigstocke, got the nod to carry on. ‘The woman died from a very different series of stab wounds,’ he said. ‘There are defence cuts on her arms and a far more haphazard pattern to the half a dozen or more wounds around her neck and chest. I’d say she was overpowered. I think she saw what happened to Allen, put up a fight and was just not strong enough.’ He looked to where Hignett was standing, anticipating the next question. ‘She wasn’t a weakling; not for your average junkie, at any rate. There was decent muscle definition…’

‘Luke Mullen does a lot of sport at school,’ Hignett said. ‘I think we can assume he would be strong enough to overpower a woman, knife or no knife.’

Thorne had heard enough. ‘Can we?’ He clenched his jaw, but still felt the blood come to his face as heads turned towards him. ‘Everyone does sport at that school, but it doesn’t mean the kid was particularly sporty… or strong. He’d had an argument with his father the morning he was snatched because he hadn’t got into the rugby team.’

‘We’re just outlining possibilities,’ Hignett said. ‘If this were an explanation of events that we could possibly eliminate, we would.’ He pointed at Hendricks, who seemed unsure whether he should sit down again. ‘None of these are answers I want to hear, trust me.’

‘Fair enough.’ Thorne was trying hard to sound conciliatory. ‘It just sounds like minds are being made up.’

Hignett nodded, but there was a nasty edge creeping into his voice. ‘This unit’s never had a case like this. We’ve had plenty of kidnaps turn into murders. Plenty. But in every case, the hostage has been the victim. It’s not usually the kidnappers that wind up dead, so I hope you’ll forgive us at this stage for considering all the options.’

‘But you’re not considering all the options-’

‘You’re the one who seems to have a closed mind on this one. You certainly don’t appear to care too much about the evidence.’

Thorne could feel the eyes on him. Brigstocke’s and Porter’s. ‘Yes, I do care. I’m not denying the fingerprints and all the rest of it, but I’m also wondering why the door to the flat was locked. Why Luke Mullen should suddenly decide to kill his kidnappers, then run off into the night, taking great care to lock the door behind him.’

‘We’re looking at that.’

‘But most of all, I’m wondering where he is. Why he hasn’t got in touch with us or with his family.’

An SO7 man, two rows ahead, piped up. ‘Perhaps because he’s just killed two people and he’s scared to come forward.’

Porter cleared her throat. ‘Or because he can’t come forward.’

Thorne felt sure that Hignett was the type who would have known exactly how to handle things were he speaking to his own team. As it was, he seemed a little unsure about how to deal with such an unfamiliar situation and looked to Brigstocke, as if they might smooth out the rough edges between them.

Thorne took it as a hopeful sign.

Brigstocke stepped forward again, ushering Phil Hendricks back to his seat as he did so, and making sure Thorne was given a good, hard look before he opened his mouth. Before he tried to move things forward. ‘Like DCI Hignett said, this is a strange one for all of us. So it’s going to be a case of suck it and see, and I’m sure we’ll make mistakes. As to the direction we move in, we’ll react to the evidence, same as we always do. With that in mind, we will have to look at the possibility that, for whatever reason, Luke Mullen killed his kidnappers. But we’ll look just as hard at a scenario involving a third party, as yet unknown, who murdered Allen and Tickell, took Luke and is now holding him at another location.’ He looked over at the SO7 man, who seemed to approve and was keen to press on.

‘Right, practicalities,’ Hignett said. He addressed his own officers. ‘Good news for those of you who live a bit further north, shitty for the rest of us, but we’ll be working mainly out of Becke House, up at the Peel Centre.’ That got contrasting reactions, from the two sides of the room. Hignett held up his hands. ‘It makes sense, I’m afraid. They’re geared up for a major murder enquiry and, for what it’s worth, Colindale’s a damn sight closer to the Mullen house. Some of you will still be working from here, but I want to avoid a stupid amount of toing and froing. You can spend half a day getting across town and we haven’t got the time.’ He turned to the area of the room in which Thorne was sitting; sarcastic but conceding a possibility at least. ‘Luke Mullen may not have the time.’

‘We need to get this going,’ Brigstocke said. ‘That means we share information and pool resources, and I see no good reason why it shouldn’t work out. We can afford to move in a couple of different directions if we choose, because ultimately they’re bound to converge.’

Now it was Brigstocke’s turn to direct a comment, but Thorne saw it coming and looked down before the DCI had the chance to catch his eye. He stared at his shoes through the rest of it.

‘Because we’re all agreed on one thing,’ Brigstocke said: ‘if we can find whoever killed those two up in that flat, one way or another we’ll find Luke Mullen.’

‘Well that was fun,’ Kitson said. Thorne and several others from the Murder Squad contingent had drifted towards the exit. Despite the somewhat fraught nature of the previous half hour, Thorne was in good spirits. He was pleased to see the likes of Kitson and Karim, happy that they would be working together again, albeit on an operation that no one had really thought through properly.

Thorne and Kitson lingered near the lifts.

‘Define “fun”,’ Thorne said.

‘OK. Relative to trapping your tits in a mangle.’ Kitson smirked, but the lightness didn’t remain on her face for long. Thorne thought she looked tired, and even further out of sorts than when he’d run into her at Becke House a few days earlier.

‘How’s this new lead on the Latif murder shaping up?’ He asked.

‘Early days…’

It seemed to Thorne as though she was searching his face for signs that he was convinced, but seeing none.

‘I fucked up,’ she said.

‘How?’

She took a few steps away from the lifts, and Thorne followed her. ‘Ever since Holland came to me with this, I’d been thinking how strange it was that Farrell hadn’t been looked at before. The E-fit that Amin Latif’s friend came up with at the time isn’t exactly a portrait – the hair’s different for a kick-off – but it’s very bloody close, you know? As close as I’ve ever seen. You look at this kid, Tom, and if you’ve got a good picture of that E-fit in your head, there’s no question it’s him.’

‘Right.’ Thorne had seen the picture, of course, but he hadn’t been near to the case. It was one of those that the team had picked up while he was still working on the rough-sleeper murders.

‘So I kept asking myself, “If it’s so bloody obvious, why did no one call up and suggest we should be interested in Adrian Farrell?” That picture was in the Standard, it went out on Crimewatch…’

‘And?’

‘And I checked… Someone did. There were two calls logged in October last year saying that we ought to take a look at him, but we never did. He wasn’t mentioned by name. It was more: “there’s a kid in my son’s class who looks like the picture I saw on the TV” sort of thing. But the school was named, and for some reason the tip was never acted on, the calls were never followed up. They got buried in the file and ignored, and ultimately, that’s down to me.’