The barman wipes the table one final time and looks him in the eye.

  ‘Then I suggest you fuck off to Finland, Jake.’

  15

  Kate

  When Kate regains consciousness, she’s staring up at the sun, her whole body swaying. Faces peer down at her, kind teenage faces full of fear and worry. Her head hurts. It takes her a few moments to realise that she’s lying on her back on the floating platform in the middle of the harbour.

  ‘She’s awake,’ one of them announces, as if the kettle’s just boiled. She loves kids, their matter-of-factness.

  ‘Here’s the lifeboat,’ another says.

  The lifeboat? For her? Kate closes her eyes again. Everyone will be watching from the shore, from the café. She likes to observe others, not be the centre of attention herself.

  ‘I’m alright,’ she says, trying to get up. But her head starts to throb and her legs buckle beneath her so she lies back down again.

  ‘It’s OK,’ one of the teenage girls says. ‘We’ve called for help.’

  ‘What happened?’ Kate whispers. All she can remember is swimming out to the platform. Why has she got such a splitting headache?

  ‘I think you had a cramp attack, almost drowned,’ the girl says, glancing admiringly at a boy standing next to her. ‘Ned dived in, brought you onto the platform. He’s done a life-saving course.’

  Good old Ned. Kate will thank him later, when she’s feeling stronger. Rob will kill her when he hears about this. And Bex. She’ll be here in a few hours, telling Kate she’s become a liability. She never used to be accident prone, but the stats aren’t looking good. Two in six months now. At least this was only cramp.

  She turns her head towards the harbour, watching as the inshore lifeboat comes alongside the platform. She can’t help feeling she’s wasting good people’s time. She was too tired. Shouldn’t have gone for a swim. Stretch will be beside himself, wondering where she is.

  As she feared, there are crowds of rubberneckers on the beach, observing the scene unfold. And a man on his own, up by the café, looking in her direction through a pair of binoculars.

  16

  Silas

  ‘This new facial-recognition software is officially shit, sir,’ says DC Strover, sitting back at her desk. ‘I assume it’s not going live anytime soon.’

  ‘That’s not like you,’ Silas says, glancing at his young colleague.

  They are in the CID corner of the open-plan Parade Room at Gablecross. Strover is an expert when it comes to computers and a champion of all things digital, constantly berating Silas for not embracing social media.

  ‘And stop calling me “sir”, will you? “Guv” or “boss” but not “sir”. Makes me feel like a schoolteacher. And I hated school.’

  Silas recruited Strover to work with him eighteen months ago. Apart from still calling him ‘sir’, she’s a quick learner, proving invaluable last year when they nailed a serial killer. He likes her sense of humour too, now that she’s grown confident enough in his company to speak her mind.

  ‘I’m a big fan of deep learning, don’t get me wrong – boss,’ Strover says, emphasising the last word in her strong Bristol accent. ‘I just don’t think computers will ever properly understand human faces.’

  ‘You’re in danger of sounding like me,’ Silas says. He’s never heard her badmouth technology before.

  ‘Airport scanners are one thing – nice, clean, head-on face shots, a constrained environment – but big unruly crowds…?’ she says. He nods, encouraging her surprising bout of heresy. ‘Forget it. Poor lighting, funny angles, grainy resolution, scarves, beards, you name it. The messy real world that the software has to work with is just too variable compared with the neat and tidy images it was trained on. I mean, take a look at this.’

  She passes Silas a printout of a mugshot. ‘That’s meant to be a match for our barman in the Bluebell.’ She pauses, letting Silas study the image. ‘My cat’s arse looks more like him.’

  Silas puts the mugshot down and sits back, smiling. She’s right about facial-recognition software, confirming his own worst Luddite fears. The system has tried and failed miserably to match the CCTV image of the barman with one of 21 million images of faces and distinguishing marks currently stored on the UK’s custody image database. And that’s after Strover narrowed the search first with the relevant metadata. He doesn’t know why they even bothered. When South Wales Police tested new facial-recognition software on crowds in Cardiff a couple of years back, 92 per cent of the matches were false. No wonder the Met, his old force, have abandoned using it at the Notting Hill Carnival.

  ‘I’ve been asking the boss for weeks if he’ll consider giving the super-recogniser unit another go,’ he says.

  ‘And?’

  ‘Not unless Kate comes back. And we know the answer to that.’

  Twelve months earlier, Silas set up a small intelligence unit to help identity criminals from Swindon’s vast database of CCTV footage. The town has more than six hundred local-authority-run cameras, making it one of the most surveilled places in Britain outside London. But the unit wasn’t about new software. It was about people, half a dozen ‘super recognisers’ – a mix of local police officers and one civilian, Kate – all of whom had been selected for their preternatural powers of facial recognition.

  Kate’s results during the screening process were ‘off the scale’, according to the professor of psychology who had overseen her assessment. He’d never come across anyone like her. And much to Silas’s delight, Kate proceeded to identify dozens of criminals in her first six months, working off grainy images and mugshots as she watched hundreds of hours of CCTV. She also operated out in the field, identifying troublemakers in large football crowds, pickpockets in shopping centres. In retrospect, Silas should have seen that she was exhausted, but everyone was blinded by her results.

  ‘Why don’t we go to Kate, instead of trying to get her to come to us?’ Strover says. ‘She might be more interested in helping, given that this involves her.’

  The same thought has crossed Silas’s mind. Kate would spot a match if there was one. Unlike this new software, Centaur, the lucrative contract for which was signed off a month after his unit was closed down. To be fair, it’s a long way off going live.

  ‘Our problem is the boss,’ he says. ‘Much as I’d like to go to Cornwall, the nail bars of Swindon are calling.’

  ‘Kate was in hospital for six weeks,’ Strover says quietly, glancing at her own nails. Silas notices a touch of sparkle. ‘If it was deliberate…’

  Silas considers again whether Kate could have been targeted. It’s been troubling him ever since his meeting with Jake at the café. After the accident, he gave Jake and Kate reassurances that no one could be arrested and charged on the basis of one super-recogniser’s word alone. But there’s no denying that a particularly violent organised crime gang are now behind bars as a result of Kate’s initial idents. And he now knows that on the night of the accident she visited a county lines pub that might have links to the same gang.

  He studies the still from the CCTV footage again. ‘I’ll go over to the Bluebell this afternoon, talk to the barman,’ he says, glancing at Strover’s screen. ‘What have you come up with?’

  ‘Looks like Kate’s living outside a village on the Roseland peninsula,’ she says. ‘South of Truro.’

  Silas knows she’s living in Cornwall, but he has never tried to find out where.

  ‘According to Companies House, all her new partner’s businesses are registered at the same address down there,’ Strover continues. ‘Nothing’s listed in London.’

  Strover tilts her laptop so that Silas can see the various websites. She’s also called up a photo of the new man. At least she’s found love. Young love. And money, by the sounds of it.

  ‘We could go down there tomorrow morning,’ Strover suggests.

  He glances across at her. Long queues on the A303, Cornish pasty for lunch. Not much of a weekend, but he’s got nothing else on and no commitments at home. An ex-wife who doesn’t want to see him and a twenty-one-year-old son, Conor, currently AWOL. He would like nothing better than to get Kate back on board, the super-recogniser unit up and running again. This time he would manage her properly. He also wants to ask her about the Bluebell, find out what she was doing there. But he knows his boss is never going to sanction a trip during office hours.

  ‘Two hundred and twenty miles, three and a half hours,’ Strover adds. ‘Maybe a bit less with blues and twos?’

  17

  Kate

  ‘Tell me exactly what happened,’ Rob says, his voice calm but concerned.

  ‘It was a lot of fuss about nothing,’ Kate says.

  She’s back at the house, lying on her bed and talking to Rob on the phone. Not on FaceTime like they usually do, just an old-fashioned call. He didn’t seem to mind that they couldn’t see each other when she rang him, didn’t ask any questions, and she didn’t offer an explanation.

  She doesn’t want to see his face, not right now, but it feels good to hear his voice, reassuring. He sounds like the Rob she knows and loves. She’s still fragile after what happened in the harbour and she’s looking forward to Bex’s arrival. She was meant to pick Bex up from Truro station, but she’s only just been given the all-clear by the paramedic who checked her over on the harbour slipway beside the café.

  ‘I was having a swim, like we always do,’ she continues telling Rob. ‘Out to the platform.’

  ‘And then?’

  ‘I got cramp in my legs, that’s all.’ She’s trying to downplay it as much for her benefit as his. She doesn’t want to dwell on how close she might have come to dying.

  ‘And nearly drowned. Doesn’t that worry you?’ he asks.

  It terrifies her. But if she admits as much to Rob, he will rush down to see her and she can’t cope with that right now.

  ‘I must still be in shock,’ she offers. Her calf muscles are almost too tight to walk.

  ‘What were you doing before the swim?’ he asks.

  ‘Having a coffee. Like we always do.’

  ‘And what did you have?’

  This is too weird. Rob interrogating her about her coffee choices. Now would seem the obvious time to quiz him about his own choices, but she can’t bring herself to ask. It suddenly seems so petty.

  ‘A flat white.’ She pauses. And then she can’t resist. ‘Ever tried one?’

  ‘Sometimes. When I’m missing you.’ His turn to pause now. ‘It’s like I’m tasting you in my mouth.’

  She blushes. And feels so foolish. He had that flat white at Paddington because he was missing her.

  ‘I had some flapjack too,’ she adds, overcome by a sudden welling-up of love for him. ‘I was famished, hadn’t had lunch.’

  ‘Were you sitting with anyone?’

  ‘Just the local village stud. We’re inseparable when you’re away.’

  ‘I’m serious.’

  ‘What’s this about, Rob?’ She’s irritated now. Must be another symptom of shock. ‘All these questions.’

  He hesitates before speaking. ‘Have you seen the papers today?’

  ‘Not yet.’ His weekend Financial Times, delivered this morning, is still lying unread on the chair in the hallway, folded like crisp pink linen.

  ‘There’s been a big trial in Swindon. Modern slavery, people trafficking. The organised crime gang was sentenced yesterday.’

  ‘And?’ But she knows already what he’s going to say.

  ‘The judge said the original arrests were made on the basis of identifications by Wiltshire Police’s super-recogniser unit. Singled it out for special praise.’

  ‘Mention any names?’

  ‘No.’

  That’s something, at least. Working on that case was addictive – and particularly draining. She knew that the trial would be coming up soon, but she’d put it out of her mind. Blanked it from her memory. That whole world is behind her now, part of another life.

  She props herself up on one elbow and thinks about the man in the café, whose face was turned away from her. She feels a pang of unease. It was just cramp, nothing more.

  ‘There was a man sitting near me,’ she says slowly. ‘I didn’t see clearly who it was. I just thought he was someone on holiday.’

  ‘What did he look like?’

  An image of the side of his face comes into focus. ‘Big forehead, dark, slanting eyebrows, receding hairline. Late forties, maybe early fifties.’

  ‘Familiar?’

  ‘I’m not sure.’

  She always used to be so certain.

  ‘It doesn’t add up, Kate, that’s all I’m saying,’ Rob says.

  ‘How do you mean?’

  ‘You’re a strong swimmer. You’d had something to eat. And then all of a sudden you get cramp so badly you nearly drown.’

  ‘I’ve had cramp attacks before,’ she says. But they both know she’s never had one like that. She’s still in denial.

  It’s a few seconds before he speaks again. ‘Did you leave your coffee unattended?’

  Jesus. She starts to panic. Was she poisoned? Stretch senses her anxiety and tries to hop onto the bed. She scoops him up and holds him close to her chest. He was in a state when Mark from the gallery dropped him round a few minutes ago. And now it’s catching up with her.

  ‘When I went to get the flapjack,’ she says, frightened by where he’s going with this, ‘I left my unfinished coffee, yes. For a minute, no longer than that.’

  Silence. Rob is annoyed, she can feel it. Eyes closed, he’s trying to control his frustration. She thinks of the café again, scared by the thought of someone spiking her coffee here in idyllic Cornwall.

  ‘You’ve got to be more careful,’ he says, gently now. ‘I’m coming back down. Tonight.’

  ‘It’s fine, really,’ she says, trying to disguise another wave of panic. She’s not ready to see him in person. She just wants to be with Bex, on her own, give herself the chance to process everything that’s been going on. She’ll tell Bex about the cramp attack, see what she thinks, whether Rob’s being paranoid.

  ‘I could drive,’ he offers.

  ‘Honestly, I’m OK.’

  She tries to tell herself that Rob is worried about her because he’s a naturally cautious person, safety conscious. It’s one of the things she dislikes about wealth. It seems to make people more fearful, oblige them to live behind high walls and locked doors.

  But she knows his worries run deeper. Rob thinks she’s in danger from the people she recognised when she worked for the police. She hasn’t told him all the details of her old job. She’s not allowed to. But he is aware that her memory for faces was instrumental in convicting some deeply unpleasant people.

  ‘You really think someone spiked my coffee?’ she asks, determined to downplay the possibility.

  ‘Maybe.’

  ‘Why would anyone do that?’ She laughs nervously, but before he has a chance to answer, she hears a car pulling up outside.

  ‘Bex is here,’ she says, grateful for the interruption.

  ‘Keep the doors locked,’ he says.

  ‘I always do,’ she lies.

  ‘And remember to set the alarm.’

  ‘I promise,’ she says, but this time she means it.

  18

  Jake

  Jake closes his laptop and looks down the narrowboat to the bedroom at the far end. There’s not much in there these days. He had a big clear-out after Kate left. A purging of sorts. The lighting is low and for a moment he thinks he sees her engrossed in a book, lying on the bed. She liked it down there, away from the noise of the engine. In the early days, she used to be his first reader, annotating embarrassing sex scenes with perceptive comments about emotional intelligence.

  A male tawny owl hoots in the woods behind the towpath. Jake gets up from his desk and walks out into the cockpit. The sky is scattered with stars, partly hidden by clouds. Is Kate looking at the same sky tonight? They used to lie on their backs in the summer, on top of the boat, making plans and dreams as they spotted the Space Station circling the earth. Two children, a country cottage with her artist’s studio in the garden, the boat kept as his writer’s retreat. It never quite worked out like that.

  A sound further down the canal. Metallic. Unusual. It’s hard to see anything in the dying light. A figure crosses the bridge by the lock gates. Someone returning from the pub, perhaps. A late dog walker. He thinks of the barman he saw today, the way he threatened him. Either he was lying and knew about Kate, or there’s something else going on at the pub that they don’t want journalists to discover. It had a strange vibe. All those CCTV cameras.

  Back inside the boat, Jake reopens his laptop. The beginning of a chapter stares back at him. He doesn’t know why he bothers to turn a good sentence these days, or agonise over an alliteration. It all gets lost in translation. Learning Finnish might be easier. Save everyone a lot of time.

  He hears another noise, closer now. Muscles tensing, he steps back out to the cockpit, stands on the seat and peers into the darkness. He’s just imagining things. It’s happened a lot recently. The boat feels so empty without Kate. Sometimes he talks to her when he’s writing, as if she were in the galley. Snippets of dialogue, passages of descriptive writing. His account of what she saw that night on the CCTV. She’s never given him a chance to explain.

  Below deck again, he calls up a photo of Rob, Kate’s new partner, trying to ignore a tightness in his chest. There are always noises on the canal at night. He holds his fingers out above the keyboard. They’re shaking. He dislikes Rob with a passion and hates himself for it. A better person than him would get on well with his successor. A man who has brought happiness to the woman he still loves, happiness that he was singularly unable to provide. He should be pleased for her. There are enough sickening reasons to like the guy – the tech fortune and his love of art, the unique blend of geekiness and entrepreneurism, his random acts of bloody philanthropy. Jake knows he ought to accept them all with equanimity, but he’s consumed with a jealousy so intense that it frightens him.