He gives her a look. She knows he’s referring to her unauthorised trips to the Bluebell. She should have told him earlier, but she’d crossed a line by going there. It was symptomatic of her state of mind at the time. She was tired to the core from work and devastated that night after seeing Jake with another woman. She also didn’t think she’d be recognised by anyone, but it seems the barman knew exactly who she was – and tried to kill her.

  And now he’s down here.

  ‘Gannets,’ Hart says, binoculars still raised.

  Strover rolls her eyes at Kate. Kate got to know her too, admired her technical knowhow, the way she stood up for herself in what was a very male environment. Hart also stood up for Strover, often fighting her corner, which is why Kate likes him. He just got carried away with the work, their successes. They all did.

  And then she spots someone on his own at the far end of the beach. He’s too far away to see his face, but his gait, his profile, is sickeningly familiar.

  ‘Binoculars?’ she says, trying to sound professional.

  Hart is still distracted by gannets. Strover nudges him. ‘Boss?’

  He passes them over. Her hands are trembling again as she focuses on the man who wants her dead.

  ‘That’s him,’ she says, lingering on his face, the features that he attempted to hide from her yesterday. Large forehead. Herman, as in Munster. Does a part of her remember him from the Bluebell, that night of the accident? Or does she just recognise him from the café and the photo?

  She hands the binoculars back to Hart. ‘To the right of the steps,’ she says. ‘Far end of the beach.’

  Hart adjusts the focus. ‘Ugly bastard, isn’t he?’

  ‘It’s definitely him,’ she says, watching as Strover pulls out the CCTV photo and passes it to her. Seeing the image again just makes her more sure. She misses this, the satisfaction of a match. It masks the fear. The professor who tested her said that super recognisers tend to peak in their mid-thirties. She should be in the zone.

  ‘Let’s have a little chat with him,’ Hart says to Strover. ‘Ask if he’s ever worked at the Bluebell.’

  They return the binoculars to the Coastwatch volunteer in the lookout and set off along the path at the top of the cliffs, heading back towards the beach. Herman is still there, but he’s not settled and their pace quickens, Hart walking out ahead. It will take them a good ten minutes to reach him.

  ‘Can I ask you something?’ Kate says to Strover, who is beside her, one eye on the beach. ‘About facial-recognition software?’

  ‘Not exactly my favourite subject at the moment,’ Strover says.

  ‘Really?’ Kate’s surprised. Strover used to live and breathe technology when they worked together.

  ‘It keeps getting it wrong,’ she says.

  ‘I thought you were the tech expert?’

  ‘It’s all relative,’ Strover says, nodding at Hart ahead.

  ‘I heard that,’ Hart says.

  ‘I just want to know how easy it would be to find your double – you know, your lookalike.’

  ‘Aren’t there apps that can do that?’ Hart asks, chipping in. ‘“Find My Doppelgänger”.’

  Hart’s not helping here. Kate’s trying to have a serious conversation with Strover, distract herself from Herman up ahead.

  ‘In theory, it should be easy,’ Strover says. ‘As you know, the software relies on metrics – the distance between eyes, ears – and data. The more of it, the better. Apps only have access to a limited number of photos. But law-enforcement agencies can draw on millions of images – the UK custody database is getting bigger every day.’

  ‘And in reality…?’ Kate asks.

  ‘You might get a rough match, but finding your long-lost twin is by no means a given. Someone who looks identical might not share the exact same facial geometry.’

  ‘It’s why we turned to people like you,’ Hart says. ‘Faces are uniquely human. They need to be interpreted emotionally, intuitively, not just measured. At least that’s what I told the boss.’

  ‘Can I ask you a favour?’ Kate says. ‘In return for helping you guys out with the photo.’

  ‘Depends what it is,’ Hart says.

  ‘I want you to look for a match for Rob. My partner.’

  ‘Isn’t that a bit weird?’ Hart says.

  Strover gives him a look.

  ‘He used to have this fear, a phobia, of meeting his double,’ she says. ‘I need to put his mind at rest, tell him there isn’t anyone out there who has the same distance between his blue eyes.’

  If Strover and Hart know she’s not being honest, they don’t show it.

  ‘What if there is?’ Strover says. ‘We’re all meant to have a doppelgänger, aren’t we?’

  Kate’s about to reply when Hart interrupts them. ‘Hold up,’ he says. ‘Our man’s on the move.’

  They all focus on the far end of the beach, a steep flight of steps that runs up to the coast path. Herman is taking them two at a time. Has he seen them? At the top, he turns and looks back across the bay. And then he starts to sprint.

  33

  Jake

  Jake stares at the French TV footage on Bex’s desktop computer in a small room adjoining the kitchen. It’s on a sliding desk, built into a bookcase. Bex said he could use it, which is helpful as he doesn’t have any data left on his phone. As far as he can tell, the geek being interviewed is Rob. And it makes for painful viewing. Rob not only comes across as intelligent and successful but charming too. And he’s speaking fluent French. Jake leans in closer. The man looks like the Rob that Jake met briefly at the hospital, but it’s not a face that he cares to remember.

  He pulls up his notes on Capgras syndrome. Ever since Bex rang earlier, he’s been researching the delusion and thinks he’s found something important.

  He calls Bex again on his mobile. Crazy. She’s been avoiding him in the village for the past six months, but now they’re like besties, bonding over the possibility that Kate might have Capgras.

  ‘Give me a sec,’ Bex says.

  He hears her talking to Stretch, Kate’s dachshund. ‘Are you with Kate?’ he asks. It’s important he talks to Bex when she’s on her own.

  ‘She’s still with the police.’

  ‘She’s not going back to the old job, is she?’

  Her police work was a far cry from portrait painting, but it gave her some independence – and money too. And it was Jake who originally introduced her to DI Hart.

  ‘No chance,’ Bex says. ‘Have you seen her house down here? The life she has now?’

  Jake falls silent. He’s often thought about visiting, trying to talk to Kate, but he has so far stayed away.

  ‘Sorry,’ Bex says. ‘That wasn’t kind. Tell me what you’ve found?’

  ‘Listen to this,’ he says. ‘“Capgras is a full-blown psychiatric disorder caused by anything from dementia to paranoid schizophrenia.”’

  ‘So why would Kate have it?’

  ‘Bear with me,’ he says, glancing at his notes again on the screen before switching to an academic paper he’s just found on the Internet. ‘From what I can gather, a super recogniser like Kate has a more developed fusiform gyrus.’

  ‘What’s that when it’s at home?’

  ‘The area of the brain that processes faces – the same area that was affected by her accident.’

  ‘And how does that relate to Capgras?’ Bex asks. Jake’s in danger of losing her.

  ‘Because Capgras can also be caused by traumatic brain injury – specifically, lesions in the fusiform gyrus.’

  ‘Bloody hell, that must be what she’s got then. It would explain everything.’

  Jake can hear the relief in Bex’s voice. ‘Except that it’s an extremely rare and unusual disorder,’ he says, reading from the article again.

  ‘Someone’s got to have it.’

  He’s still not convinced. ‘And it doesn’t seem to affect the auditory cortex, just the visual.’

  ‘Say that bit again,’ Bex says, a sudden curiosity in her voice.

  ‘Someone with Capgras only thinks their loved one is a double if they can see their face,’ he explains. ‘If they can only hear their voice, it doesn’t seem to affect them.’

  ‘When they’re talking on the phone, you mean?’

  ‘I guess so. Why?’

  ‘Because Kate says she’s fine when she’s chatting to Rob on her mobile. It’s when he facetimes her and she can actually see his face that she freaks out.’

  Jake sits up in his chair, trying to get his head around what Bex has just said. ‘You really need to speak to her about this,’ he says. Up until now, the Capgras theory has seemed interesting but a little fanciful. He now thinks they might be onto something, given her past as a super recogniser. It would be a cruel irony if a high-performing fusiform gyrus, once responsible for Kate’s exceptional powers of recognition, was now tricking her into seeing doubles.

  ‘She’s seeing a neuropsychiatrist regularly,’ Bex says. ‘Paid for by Rob. I’ll get her to ask him about it. I don’t think she’s mentioned seeing doubles to him yet.’

  Jake hangs up and starts to search for more information about Capgras: case studies, related delusions like Fregoli (different people are in fact a single person who changes his or her appearance), but something’s still nagging him about Rob. He’s just not sure what. He begins to google him, repeating a search he’s done many times in recent months. Brought up by two doctors in Douglas, Cork, entered the Sunday Times Irish Rich List when he was twenty-three. Always considered a bit of a loner. After a few minutes, Jake is on the Companies House website, looking at a list of all Rob’s directorships: technology start-ups, mostly medical, an online art gallery. He’s been here before and found nothing suspicious. The only controversy was when he briefly invested in a company that made electric-shock collars for training dogs. The product was banned before it even hit the shelves.

  This time, though, a new company is listed, the one mentioned in the news report. He pastes its name into a separate Google tab, calls up the website and clicks on ‘About’. The company appears to specialise in something called ‘direct neural interface technology’. It’s currently raising capital for electrodes implanted in the brain that can help to operate artificial limbs or control epilepsy.

  A window asks him to accept cookies. He clicks on it and is about to drill down further into the site when he notices a green LED light on Bex’s computer, just to the right of the camera. He’s sure it wasn’t on a moment ago. His first thought is that maybe Bex does a lot of facetiming and someone’s calling her. But FaceTime isn’t open. He closes the company website, quits Chrome and backs away from the computer. The light is still on, the camera watching him.

  34

  Kate

  ‘You go on ahead,’ Hart says, calling out to them. ‘See where he goes.’

  Kate’s walking fast beside Strover. They glance at each other and both slip into a run. Hart’s heavy breathing fades behind them.

  ‘This really isn’t part of my Cornwall retirement plan,’ Kate says as they stride out together on the coast path.

  ‘You do the identifying, let us do the rest,’ Strover says. ‘Just like the old days.’

  Kate’s glad she’s been getting fit. As well as the swimming, she’s tried to run two or three times a week, on the same stretch of coast path as they’re on now. Strover seems fit too, though she’s not exactly in running gear. Light trousers and those telltale sensible black shoes that only plainclothes cops seem to wear.

  ‘I’ve lost him,’ Strover says, coming to a halt. ‘Can you still see him?’

  The coast path ahead broadens out into a wide grassy track, ridged with trails left by sheep. There are one or two walkers, but most people are enjoying the sea and the sand below. It’s what Kate should be doing on a beautiful day like today, not running beside a detective in pursuit of a man who keeps trying to kill her. Beyond the grassy expanse, where the steps come up from the beach, the path weaves its way through gorse bushes. For a moment, she can’t see Herman either and then he appears again from behind a bush, close to where the path enters the village.

  ‘He’s up by the first houses,’ she says, getting her breath back.

  ‘If he’s got a car, we’re stuffed,’ Strover says.

  Five minutes later, they’re walking quickly through the village, scanning every side road and alley for the man. Strover’s already called Hart, given him an update. They try not to draw attention to themselves as they pass holidaymakers coming up from the beach laden with chairs and spades and buckets.

  ‘He could be anywhere,’ Kate says.

  ‘Problem is, we’re not officially here,’ Strover says. ‘Otherwise I’d call for back up.’

  ‘How do you mean?’ Kate glances at Strover.

  ‘We’re off duty.’

  She gives Strover a puzzled look. She’d assumed they were down on official business.

  ‘Sad, I know,’ Strover says. ‘Daytrip to the seaside with my boss at the weekend. Such is the miserable state of my social life.’

  ‘Why are you really here, then?’

  Strover looks out to sea, her neat, petite face glowing from the exercise, and then turns to Kate. ‘He was devastated when you were injured. We all were. When we saw the CCTV footage yesterday of you at the pub that night, he felt he had to investigate. In his own time.’

  ‘Because his boss wouldn’t have sanctioned it?’

  Strover nods. Kate remembers his boss, the one who never believed in the super-recogniser unit, despite their results, and closed it down soon after her accident.

  ‘Why now, though?’ she asks. ‘How did you suddenly get the CCTV footage?’

  She doesn’t expect Strover to answer. She learnt quickly that as a civilian she was not allowed to know the operational details of the cases she worked on.

  ‘Jake didn’t mention it, then?’ Strover says.

  ‘Jake?’

  ‘It was him who was sent the video.’

  Why would Jake be sent CCTV footage of her at the pub that night? ‘Who by?’ she asks, her head spinning.

  ‘We don’t know.’

  ‘When?’

  ‘Yesterday.’

  ‘And someone sets fire to his boat last night?’ There must be a connection. Kate lets her words hang in the air, hoping Strover will join the dots.

  ‘I can’t tell you any more. I’m sorry,’ Strover says. ‘Trust me, we’re working on it.’

  They jog down into the village, stepping out into the middle of the road to avoid a crowd of children coming up the other way. They’re all eating ice creams, peering into a small beach bucket. That’s why Kate loves it here, a reminder of her childhood, of innocent days spent rock-pooling, building sandcastles. She just wishes that her past hadn’t caught up with her. The spiked coffee, Jake’s fire, the CCTV image of her at the pub. And a crazy, nagging sense that Rob’s been replaced by a double. Overnight her idyllic life’s become a nightmare.

  ‘Caught a shark?’ she says as they pass the children, glancing at their catch.

  ‘Crabs,’ one of them says, holding the bucket out for her to see.

  Strover looks too, smiling at the young children. At the bottom of the bucket is a modest crab, its shell barely three inches across.

  ‘Massive, isn’t it,’ another child says. ‘Tried to bite me with its huge claws.’

  Kate hears the car first. They are both still in the road, the children on the pavement. And then she’s aware of Strover screaming at her, so loud it’s as if her voice is in her own head.

  ‘Watch out!’

  She spins around to see a car coming up the hill, out of the village, driving too fast. Instead of slowing down, or moving across to the other side of the road, it accelerates, the driver steering directly at her and Strover. Strover moves first, pulling Kate out of the way just in time, but not before Kate gets a look at the driver, who turns to glare at her. It’s the same man, same forehead. Herman.

  The car speeds past, its wheels inches from the pavement.

  ‘Emmet!’ someone shouts from across the street.

  ‘Get the number plate,’ Strover says as she picks up one of the kids she accidentally knocked over when they jumped onto the pavement.

  Kate memorises the plate and the make of the vehicle, a BMW. She’s hopeless with cars and only happens to know it because Jake used to want one when they were at their poorest. In his dreams.

  ‘Who was that?’ one of the children asks.

  ‘Just an angry fisherman,’ Kate improvises, her chest tight with adrenaline. She can hardly breathe.

  ‘Why’s he so angry?’ another child asks.

  She tries to calm herself. Her legs have turned to jelly.

  ‘Because he didn’t catch what he wanted,’ she manages to say, peering again into their bucket to distract herself. As she holds its rim, one of the children looks up at her, aware that her shaking hand is creating ripples in the bucket’s water. She manages a smile, struggling to stop herself being sick. The car tried to run her down, could have killed the children.

  ‘Must have been jealous of your massive crab,’ she says.

  35

  Silas

  ‘Sure the kids are OK?’ Silas asks Strover as he sips on an espresso. The harbour café is full of families in dripping swimwear and sunglasses, the air thick with the smell of sun lotion and salt water.

  ‘All fine. Apart from the one I squashed,’ Strover says. ‘He’ll live.’

  After a long talk with Strover, Kate has gone back to her house, shaken up by the near miss. They’ll call on her on their way out of the village, check again that she’s alright.

  Silas was hurrying down the hill when the car sped past. He managed to get its number plate, which tallies with the one that Kate memorised. A minute later, he was with Kate and Strover on the pavement, relieved that no one had been injured.

  ‘If he knows we’re police, he’ll ditch the car – or lose the number plates,’ he says.