He addressed them both this time, but Porter answered before Styles felt compelled to. His partner was one of the most intelligent people he knew, but he was still wet around the ears when it came to dealing with office politics.

‘We were finishing up an interview with Mrs Locke, sir. We didn’t get the opportunity to finish it a few days ago, and needed to ask her a few more questions to get background on her stepdaughter.’

‘And by collecting background, you of course mean accusing one of her husband’s employees of being complicit in her disappearance?’

Porter lowered his gaze for a second as he sifted through the possibilities. The only one that made sense was that Mrs Locke had called up and complained after they had left.

‘Sir, I don’t know what she said exactly, but we were very respectful, and as soon as she asked us to leave we—’

‘She didn’t say anything. He did, or should I say his solicitor did on his behalf, asking why we’re harassing his wife and accusing his staff without proper cause or foundation.’ His tone was no different to that he used in day-to-day conversation, but the way he enunciated reminded Porter of a schoolteacher.

‘I then had the pleasure of a call from Deputy Commissioner Nesbitt, asking why we’re aggressively pursuing a case with so little evidence, against a man of Locke’s standing. That puts me in a difficult position, Porter. I either back your play and look like a fool for doing so with insufficient evidence, or I tell him you operated against explicit instructions and look like I can’t command my own men. Which would you have me do? That’s a rhetorical one, by the way.’

Campbell paused for breath and glanced at Milburn, who wore a relaxed smile, presumably thinking about his own stock rising as Campbell fought to defend his own name.

‘Sir, if I may?’ Porter hoped to mitigate whatever censure was coming by sharing his observations about the inconsistency at the crime scene, and the possibility of footage of the street. If he could convince them of the case against Bolton for Gibson and Simmons, he might be able to trump their desire to use the big man as part of the drugs case. The publicity that would come of jailing a cop killer was something surely even Campbell couldn’t pass up. Locke was all theirs as far as he was concerned but every instinct he had screamed out that Bolton was their man for both of his colleagues, as well as Natasha.

‘No, Detective, you may not.’ Milburn took over now. ‘While you and your partner have been harassing Mrs Locke, your friends here’ – he gestured towards Anderson and Whittaker – ‘have been doing some worthwhile police work.’