DCI Digby hadn’t changed much in the four years since Kelly had last seen him. A little greyer around the temples, perhaps, but still young for his age, with the sharp, perceptive eyes Kelly remembered so well. He wore a well-fitting suit with a pale grey pinstripe, and shoes that shone to military standards too engrained to ever be forgotten.

‘Golf,’ he said, in response to Kelly’s compliment. ‘Always swore I’d never spend my retirement on the golf course, but Barbara said it was that or a part-time job – she didn’t want me under her feet all day. Turns out I rather enjoy it.’

‘How long have you got left?’

‘I retire in April next year. I thought about staying on, but the way we’ve been shafted lately, I’m glad to be going, to be honest.’ He took off his glasses and rested his forearms on the table between them. ‘But you didn’t call me out of the blue to find out my retirement plans. What’s going on?’

‘I’d like a secondment to Operation FURNISS,’ Kelly said.

The DCI didn’t speak. He looked appraisingly at Kelly, who didn’t flinch. Diggers had mentored Kelly when she had first joined the job, taking her on as a DC on the Sexual Offences Unit, where he was the detective inspector.

Outstanding candidate, her board feedback read. A tenacious and perceptive investigator, with high levels of victim care and clear potential for the next rank.

‘Sir, I know I messed up,’ she began.

‘You assaulted a prisoner, Kelly. That’s more than messing up. That’s six months inside, on D wing with the narks and the nonces.’ Her stomach knotted: the ball of shame and anxiety that had followed her around for the last three years.

‘I’ve changed, sir.’ She’d had counselling; six months of anger management classes that had served only to make her more angry. She’d passed with flying colours, of course; it was easy to give the right answers when you knew the game to play. The real answers would have been less palatable to the police-payroll therapist, who claimed not to judge, but had visibly blanched when Kelly had answered the question How did it feel to hit him? with It felt good.

She’d kept the truth to herself from that point. Do you regret your actions? Not in the slightest. Could you have taken any other course of action? None that would have given me such satisfaction. Would you do it again?

Would she?

The jury was still out.

‘I’ve been back for two years, now, boss,’ she told Diggers. She tried a small smile. ‘I’ve served my time.’ Diggers either didn’t notice, or didn’t appreciate, the joke. ‘I’ve recently finished a three-month attachment to the Dip Squad, and I’d like to get some experience of a Murder Investigation Team.’

‘What’s wrong with doing that in your own force?’

‘I think I’d learn a lot from working in a Met environment,’ Kelly said, the grounds for her request prepared in advance; slipping easily off the tongue, ‘and I know you’ve got one of the strongest teams.’

The corners of Diggers’ mouth twitched, and Kelly knew she wasn’t fooling him. She held up her hands.

‘I’ve already asked the Murder Investigation Team at British Transport Police,’ she said quietly. ‘They won’t touch me.’ She forced herself to maintain eye contact; not to show him how ashamed she was, how hard she found it that her own colleagues didn’t trust her.

‘I see.’ There was a pause. ‘It’s not personal, you know.’

Kelly nodded. It felt personal. Other uniformed officers were seconded to CID and MIT when extra resources were needed. Kelly never was.

‘They’re worried about no smoke without fire. They’re worried about their own jobs, their own reputations.’ He paused, as though he was debating whether to say something. ‘And maybe they’re just feeling guilty by association.’ He leaned forward, lowering his voice until Kelly could barely hear him. ‘Because there isn’t a man or woman in this job who hasn’t at least once wanted to do what you did.’

Seconds passed, before Diggers broke away, shifting position and bringing his voice back to a normal level. ‘Why this case? Why Tania Beckett?’

Here, Kelly was on firmer ground. ‘The case is linked to a theft on the Underground I picked up while I was working with the Dip Squad. I’ve got a relationship with the victim already; I’d like to see the job through. If it hadn’t been for my input, the series wouldn’t even have been identified, yet.’

‘What do you mean by that?’

Kelly hesitated. She didn’t know what the DCI’s relationship was with Nick Rampello. She hadn’t taken to the guy, but she wasn’t about to grass up a colleague.

Diggers picked up his coffee, took a large and noisy swallow, then set his mug down on the table. ‘Kelly, if you’ve got something to say, spit it out. If this was entirely above board you’d be speaking to me in my office, not ringing my mobile for the first time in four years and suggesting we have coffee in this …’ he looked around the café, taking in the shabby counter and the peeling posters on the wall, ‘glamorous establishment.’ A tiny lift at the corner of his lips mitigated the harshness of his words, and Kelly took a deep breath.

‘A woman called Zoe Walker contacted me to say a photo of Cathy Tanning appeared in the classifieds of the Gazette, and that her own photo had appeared a few days previously.’

‘This I know. What’s your point, Kelly?’

‘It wasn’t the first time she’d told the police about the two photos. Zoe Walker rang MIT the day Tania Beckett’s murder was reported.’ Kelly carefully avoided naming DI Rampello. ‘The team responded to the information by investigating Tania for connections to the sex industry but failed to draw any inference from the fact Mrs Walker’s own photo had been used in a similar advert without her permission, with no link whatsoever to chatlines or dating agencies. They didn’t accept we had a potential series; not until I insisted.’

Diggers didn’t speak, and Kelly hoped she hadn’t overstepped the mark.

‘They?’ he said eventually.

‘I don’t know who Zoe Walker spoke to,’ she said, taking a sip of her own coffee so she didn’t have to meet his eyes.

Diggers thought for a moment. ‘How long would you want?’

Kelly tried not to let her excitement show. ‘As long as it took.’

‘That could be months, Kelly. Years, even. Be realistic.’

‘Three months, then. I could add value, boss, I wouldn’t be a dead weight. I can handle the BTP liaison, all the Underground work …’

‘Will BTP release you for that long?’

Kelly could imagine how Sergeant Powell would react to such a request. ‘I don’t know, I haven’t asked. I hoped that with the right approach, at a senior level …’ she trailed off, meeting Diggers’ gaze.

‘You’re expecting me not only to authorise a placement for you, but to smooth the way with your own superintendent? Christ, Kelly, you don’t do things by halves, do you?’

‘I really want this, boss.’

The DCI fixed his gaze on her so intently she had to drop her own. ‘Will you be able to handle it?’

‘I know I can.’

‘I’ve got a good team up at Balfour Street. They’re a close-knit bunch, but they’re experienced detectives; they can all work on their own; they can all withstand the pressure of an intense investigation.’

‘I’m a good copper, boss.’

‘They can all handle emotionally difficult cases,’ he went on, and this time there was no ignoring the emphasis.

‘It’s not going to happen again. I give you my word.’ Diggers drained his coffee. ‘Look, I can’t promise anything, but I’ll make some calls now and if BTP will release you, I’ll take you on a three-month secondment.’

‘Thank you. I won’t let you down, boss, I’ll—’

‘On two conditions.’

‘Anything.’

‘One: that you do not work alone.’ Kelly opened her mouth to argue that she didn’t need a babysitter, but Diggers cut in again. ‘It’s non-negotiable, Kelly. Yes, you’re an experienced officer and a good detective, but if you join my team, you’re on probation. Do you understand?’ She nodded.

‘What’s the other condition?’

‘The second you feel you’re losing control – the second it happens – I want you out of there. I saved your neck once, Kelly. I won’t do it again.’