‘And just what have I done, Detective? Apart from get shot by a man I trusted for years? What exactly do you think I’m guilty of?’

‘More than I’ll ever be able to prove,’ said Porter wistfully. ‘But not even you can walk away from the mess you left back there at Atlas without mud sticking. And that’s before we even get started on Natasha. I’ll make damn sure you take your fair share of blame for what happened to those officers today.’

‘We’ll never get to the bottom of what happened to her now James is dead, will we? You lot have seen to that.’

‘Jimmy seemed pretty adamant he had nothing to do with that. He seemed to think you might know more than he did. Now why would he think that?’ Porter asked, leaning back against the counter, folding his arms.

‘After what he did to those officers today, who knew what was going through his mind.’

‘That’s just it, though. If we’d taken him in for that he’d have gone down for life, no doubt about it. So why get on his high horse about Natasha? What’s one more murder in the grand scheme of things?’

Locke shrugged, screwing his eyes shut as the pain lanced through his arm with the movement. ‘No idea. Not my problem. So, you mentioned a hospital. Why don’t we head there, and I can call Mr Jasper on the way?’

Porter ignored the request. ‘See, that’s where we disagree. I think it is your problem. There’s something that’s been bothering me about what we found at her flat. One thing that didn’t make sense.’

‘And what would that be?’ said Locke, his voice weary now.

‘We found blood on the carpet. Blood that didn’t match Natasha, but more importantly, it didn’t match James Bolton either.’

‘So?’

‘So what that tells us is that somebody else was in her apartment when her blood was spilt. Could be Olly Davies, could be someone else.’ Porter paused. ‘We haven’t taken a sample from you, yet, Mr Locke. Bolton was adamant he had nothing to do with her death. Looked pretty pissed off that I’d even suggested it, to be honest. No, what I’m wondering is what would show up if we tested you?’

Locke coughed, wincing as a fresh jolt of pain washed over his face. ‘Do what you like. No matter how much you want to believe I was there, I wasn’t, and you can’t prove otherwise.’

There was something in the way he said it, sounding so blasé that it made Porter pause. If not Locke, then who? Mary? No. What reason would she have had to lie about this? To hurt Natasha herself? He remembered what she had said about Ruislip Woods. The fourth man.