Persons Unknown: A Richard and Judy Book Club Pick 2018. Susie Steiner

away from all future briefings. And you’re not allowed to search the database or ask officers about the case.’

      ‘He really needs to calm his tits,’ Manon says to Harriet.

      ‘That’s enough, you two,’ says Harriet.

      Manon realises Davy wants to tell Ellie himself so he can watch her, see how she reacts. Everyone close to the victim is a suspect and how they take the news is part of a close-circuit observation that is often disguised as sympathy and support. We are giving you a liaison officer to keep you informed/watch your every move and report it back to the investigation.

      ‘One more thing, Manon,’ says Davy. ‘Where was Ellie yesterday afternoon and evening?’

      ‘Am I being interviewed?’ asks Manon, placing a protective hand on her bump. ‘Because if I am, I want all the proper gear – recording device and everything.’

       Davy

      ‘Should we put a trace on Judith Cole’s phone?’ he says, now that he and Harriet are alone. ‘See what she was really doing in the woods at that time? Kim thinks she wasn’t walking the dog.’

      Harriet has closed the door to her office and is pacing, the wings of her jacket pinned back by her hands on her hips. ‘Nah, Judith Cole’s not the issue. Woman from across the road who didn’t know him? Who cares what she was doing in the park? We don’t have grounds for a trace.’

      ‘Except her being the last person to see him alive, and also lying,’ Davy points out.

      ‘Yes, but she might be lying for some other reason. Just because she called it in, doesn’t put her in line for investigation – you know the Samaritan rule. Priority is questioning Ellie Bradshaw. She’s the person who can give us the most on Ross – who he was, who might have wanted to stab him.’

      ‘What are our main lines, boss?’

      ‘I’d say financial work and exes – so that’s Ellie. And the photo in his jacket – the blonde. We need to find out who she is. Maybe she’s Sass. There’s a strong money motive, with someone like him.

      ‘Judith Cole has come in for re-interview,’ Davy says.

      ‘Has she? Right, OK, you can have another go at her – gently, Davy – just to fill in the gaps in her statement while we wait for Ellie Bradshaw to come in. But no more than that – husband’s a lawyer, I don’t want a complaint. And Davy? Take Kim with you. Sounds like she was doing a very good job last time.’

      Davy is upended by jealousy, like a small boy in rough surf, while the adult in him says, ‘Righto, boss.’

      ‘Your husband says you weren’t walking the dog,’ Kim says, as soon as the bleep sounds, without warning or preamble.

      Judith Cole blanches to the colour of her semi-sheer white blouse, which has a white vest visible beneath. At her throat is a sparkling pendant, a single diamond on a silver chain. Unlike the last time they saw her, she is freshly blow-dried and wearing immaculate makeup.

      ‘I did have the dog,’ she says, though Davy hears uncertainty in her voice. ‘He must be mistaken.’

      ‘Why would you walk over a busy main road to Hinchingbrooke Park when there’s a nicer one at the end of your road, which is nearer?’ Kim asks.

      ‘I don’t think it’s nicer,’ says Mrs Cole. ‘I like Hinchingbrooke Park. I can let the dog off the lead and he can run around.’

      ‘It was pitch dark though,’ says Kim. ‘Seems a bit odd.’

      ‘Yes, it was dark, but it wasn’t late – only four-ish. Do you have a dog?’ Mrs Cole asks.

      Kim and Davy are silent.

      ‘Well, you see, if you had a dog, you’d know that owning one means venturing out in snow, hail, darkness, you name it. A dog’s gotta do what a dog’s gotta—’

      ‘Davy?’ Harriet is at the door. ‘A word, please.’

      He and Kim step outside.

      ‘CCTV from King’s Cross has come in. I’d like you to take a look.’

      ‘Right, so there’s Ross,’ Harriet says, pointing at the screen. They are standing around Colin’s computer, looking at the grainy images of King’s Cross station platform as people make their way to board the train.

      Davy watches Ross put his ticket into the barrier and walk through it. He strides down the platform with confidence, coat well cut. He looks like a businessman on his way to a meeting that will not challenge him greatly. His face is unfazed, neither angry nor anxious. How little we know of what lies ahead.

      ‘Look at this fella,’ Harriet says.

      ‘Who?’

      Harriet is leaning over Colin and tapping on his keyboard to set the tape back a few frames. ‘There.’

      She points at a big man, bald with a black smudge at his ear, possibly an earpiece. He wears a bomber jacket and underneath it he is stocky and muscled, causing his arms to sit wide. The image quality is poor. He is coming through the ticket barriers shortly after Ross.

      ‘He’s looking at Ross like he’s dinner,’ Harriet says.

      Even on grainy CCTV footage, they can all see the man’s focus is on his quarry, who is just ahead of him. He glances down briefly to get his ticket from the barrier, but then his eyes are back on Ross, hurrying to keep up with him and then boarding the same carriage.

      ‘Who is he? That’s what we need to find out,’ Harriet says.

      They all straighten, away from the screen.

      ‘I’ve looked at the Huntingdon CCTV and this chap does not get off the train with Ross, so where does he get off? That’s question one,’ Harriet says. ‘And where does he go? It’s identifying him that’s going to be the problem.’

      ‘What’s the timing on that?’ Davy asks. ‘We need to get the information off that ticket machine.’

      ‘So, Ross goes through the barrier at 3.08 and forty seconds. The other guy is going through twenty seconds later, so at 3.09 p.m. exactly. We’re going to need the station staff to identify whether his ticket was bought with a card.’

      ‘Might’ve paid cash,’ says Davy. ‘We should also capture the rest of his journey at the London end, off station CCTV and underground, roads.’

      ‘We could email his picture to local forces, see if anyone recognises him,’ Kim suggests.

      ‘How about Crimewatch?’ Davy says. ‘Do you know this man?’

      Everyone groans.

      ‘I don’t think we’re ready to be buried in a gazillion false leads just yet,’ says Harriet. ‘But he’s marking him, right? I mean, he’s definitely marking him.’

      The others nod, Davy regretting he is not more reassuring in the face of her need for it. There is so much to do, so many tiny steps to complete in just this fragment of the case. He can feel himself getting into a state, a feeling of panic which renders him inactive when what he needs to do is hurry up. And forensics will be in tomorrow, which will present them with still more avenues for inspection. And he hasn’t even resolved the dog-no-dog question and the small matter of why Judith Cole is lying. Not to mention the fact he’s starving. And who, or what, is ‘Sass’?

      ‘Are you all right, Davy?’ Harriet asks.

      He realises he has been rubbing his brow and frowning at the floor.

      ‘Yes boss, I’m fine. Just wondering where to begin,’ he says, with a weak smile. He wishes his