‘Wait for me in here,’ Kate said, as Finn sat in the soft interview room. ‘I’ll check that the suspect is still here and then I’ll set up a chance for you to identify him. Do you want tea or coffee?’

Finn didn’t look comfortable in the confines of the windowless room, and Kate had to question whether she was doing the right thing in putting him through such an ordeal. If he was right, and Isbitt was the engineer who’d fixed Amy’s computer, she would be putting him face-to-face with his sister’s killer, and that wouldn’t be easy.

He shook his head. ‘Don’t be long.’

She tried to smile reassuringly. ‘I’ll be as quick as I can.’

Closing the door behind her and marking it as engaged, she made her way back along the corridor, and up to the third floor to look for Laura when she heard a familiar boom.

‘MATTHEWS! Get in here. NOW!’

Kate shut her eyes and took a moment to compose herself before turning and heading through the supe’s open door. She remained silent as he paced furiously by the large window overlooking the sea. He finally slowed, stooping to rest both hands on his desk, clearly exasperated.

‘Well? What’s the explanation this time?’

She hesitated, uncertain which specific actions he was referring to.

‘Have you nothing to say for yourself?’

She remained silent, her head dipped.

‘Okay, well I’ll start, then. Tell me on whose authority did you approach DCI Armitage and discuss a case that you’ve been warned to go nowhere near?’

So Armitage had followed through with his threat, she couldn’t say she was surprised. ‘Sir, I have reason to believe that the suspect you currently have in custody is the man responsible for not only the two women killed last week, but also the four women murdered in London a year ago, including DC Amy Spencer.’

The supe looked like he might erupt, but she carried on before he had a chance.

‘Hear me out. We believe that the same person killed Helen Jackson and the woman discovered in the car park on Saturday night, whose name we now believe to be Mary Eden, from a dating website that both her profile and Helen’s were found on.’

‘Who’s we?’

‘DC Trotter and myself.’

He threw his hands into the air in mock surprise.

‘So, not only are you breaching procedures, you’re dragging the ever-eager Trotter down with you.’

‘Sir, if you—’

He held up his hand to silence her. ‘No, enough is enough, Matthews. I’ve given you the benefit of the doubt since that Vaughn mess last year, but you’ve taken advantage of that, and it has to stop. You’ve crossed the line this time.’

‘But, sir, please, we suspect Isbitt was at Amy’s flat—’

‘I warned you about this on Thursday. This was precisely what I was trying to avoid.’ He turned his back to her and stared out at the sea. ‘I understand the frustrations of not solving a case that you’re personally invested in. With your own involvement in what happened a year ago, I can see why you would want to find links between what happened then and now. If you could link the crimes, you’d have the closure your mind demands. But as your superior and friend, I need you to listen very carefully to what I am about to tell you: let it go.’

‘But, sir, if you’ll just—’

He spun round. ‘There is no connection! We released Isbitt half an hour ago. He has an alibi for Saturday night. He didn’t murder the second victim.’

‘But, sir—’

The hand flew up again. ‘I made it abundantly clear to you that you were to go nowhere near Underhill’s investigation. Even when you disobeyed and tried to take control of the second murder, I reminded you of my expectations. And despite all those chances, you continue to defy me!’

‘Sir, I’m not—’

‘I don’t want to hear anything else from you, Matthews. You’re done here. I have already spoken to Professional Standards and they support my decision to suspend you from duty with immediate effect. You’ve left me no other choice. You are hereby suspended as per regulation 10 of the Police (Conduct) Regulations 2012. Your suspension will be on full pay and will last until such time as a hearing can be arranged. I will confirm the terms of your suspension in writing in the next day or so.’

Kate remained where she was, until he pointed to the door. With her head low, she left his office, slamming the door behind her. She’d come too far to stop now. Amy’s killer was free, and it was her duty to nail him once and for all. Even if it cost her the only job she’d ever loved.