If They Knew: The latest crime thriller book you must read in 2018. Joanne Sefton

shrugged. ‘Open data. Citizen journalism. Crowd science. None of it makes a jot of sense to me, but she’s always got something going on. Keeps her sharp, she says, and I suppose it seems to work.’

      They heard the computer power down and then Barbara emerged on the stairs. She and Neil went out to the car. Helen took the children to wave at the window. Neil’s face was strained and she regretted not taking the chance to ask him how he was whilst Barbara was busy. Still, it underlined Barbara’s point about the notes: he wasn’t a man who needed anything extra to worry about.

      Pat from next door rushed over to the car with a card in her hand and both Neil and Barbara looked to be trying hard to seem pleased to see her, without managing to succeed.

      Normally, Helen only insisted the kids come to the window to wave when the grandparents had been staying with them and were leaving to drive home. Barney was clearly bored by waiting for them to actually get into the car and couldn’t get back to CBeebies quickly enough. Alys, though, was confused.

      ‘Granddad Neil and Nana Barbara go to our house?’ she asked, as the car finally pulled away.

      ‘No, Nana is going to hospital for a few days. Granddad will be back later.’

      ‘And Nana.’

      ‘No, just Granddad.’

      ‘Granddad can come to our house.’ She was nodding firmly, as if that decided it.

      ‘No, we need to stay here a bit longer. We need to wait for Nana to come home.’

      ‘Daddy come here.’

      God, thought Helen, please don’t start this now. ‘No …’ she began patiently, getting ready to explain once again.

      ‘Not no!’ Alys shouted. ‘Daddy come now!’

      She was pointing out of the window. Helen hadn’t even registered the car that had pulled into the cul-de-sac a few moments after Neil’s Nissan had turned out of it. It was a silver Astra, badged up by a hire company.

      Fuck. Alys was right. He was three days early.

      Darren jumped out of the driver’s seat and bounded onto the drive, before catching sight of them in the window and veering across the lawn, waving at Alys.

      Frantically, Helen strained to see if there was anyone else in the car, but he seemed to be alone. Alys’s voice rose to a clamour and by this time Barney had left the television and was hauling himself up to stand on the sofa and see what was going on.

      ‘Daddydaddy‌daddydaddy‌daddydaddy‌daddydaddy.’

      ‘Feet down, please, Barney.’

      He ignored her and the volume of the children’s joyous duet surged ever upward. Darren didn’t disappoint, miming his excitement through the double glazing whilst studiously failing to meet Helen’s eye.

      Of course, she had no choice but to let him come in. After as few terse words as she could manage, Helen left the living room and let the three of them get on with it.

      She went to the spare room first, but that immediately felt wrong, so instead she crept upstairs and into the womblike snugness of her childhood bedroom. She sat in the corner of the single bed, leaning against the wall, with Barney’s precious blanket tucked between her knees, straining to listen and to keep the tears from falling.

       Bastard. Bastard. Bastard.

      *

      Helen studied the lilac, swirly wallpaper she’d picked out when she was fourteen, trying to match up the ghostly, faded squares with the posters and pages ripped from magazines that had once decorated her walls. Michael J. Fox over there, later replaced by John Squire. George Michael, replaced by John Squire. She pictured the various incarnations, trying to switch off her brain.

      Eventually she heard his footsteps on the stairs. He’d lasted about forty-five minutes, which was more time than he’d spent alone with Barney and Alys together in as long as she could remember, not counting soft play. He opened the door without knocking and walked into the room. She stayed hunched up on the bed, looking over his shoulder instead of directly at him, but still catching the look of mild pity as he gazed down at her.

      ‘What the fuck do you think you’re doing turning up here?’ she asked.

      It wasn’t brilliant, but she was proud that she had managed to spit it out, past the lump in her throat and the decades of conditioned politeness. Darren didn’t answer immediately, probably weighing up his options.

      ‘They’re my kids. I had to see them, Helen. I didn’t have any choice.’

      ‘Well now you’ve seen them.’

      She was going to add ‘fuck off’, but in the end it seemed too crude, too teenage. The pair of them fell into silence. Then Darren dropped down to a sitting position, closing the door to lean his back against it and laying his long legs out across the only stretch of carpet in the tiny room where they fitted. He should know. Years ago, he used to play guitar sitting like that for hours, while she was revising or reading or just watching him. Hard to believe it was the same person.

      ‘My mum said Barbara’s going in today, that the op’s tomorrow?’

      ‘I’d like you to leave.’

      He bit his lip and then put a finger to it. For a moment, she sensed he was about to slam his hand against something, but he seemed to hold himself back.

      ‘I miss you, Helen.’

      She said nothing.

      ‘I know I chose this, I know it’s my fault. But that doesn’t mean I don’t miss you. We grew up together, didn’t we? No one knows me like you do, and I know what you’re going through as much as anyone can. I’m sorry about it, Hels, I really am.’

      ‘Are you asking to come back?’

      Now it was Darren’s turn for silence. He wriggled an index finger into the pile of the carpet and stared at the holes he was making.

      ‘We’ve been through all this,’ he whispered. ‘You know it’s not been right for ages. This is better for both of us.’ But then he rushed on, whip-quick, as if to head off any disagreement from her. ‘But the point is I can help you. And I want to. For the kids. And for us, for everything we were. You’ve got to let me, Hels.’

      She shouldn’t have agreed, she thought later.

      In truth, she didn’t agree. She didn’t say anything. But her silence was acquiescence enough.

      She let him bring her a cup of tea and put the kids in front of a film. She let him sit on the single bed next to her, the weight and the smell of him on the homely sheets just as intoxicating and incongruous as it had been twenty-odd years earlier. She poured out the details of surgery and staging, metastasis and Macmillan nurses. She even told him about the green notes. He seemed perfectly happy with Barbara’s explanation about the teenage shoplifter. ‘There are some fucked-up weirdos in this world, Hels.’ He laughed. ‘That’s one thing you learn running a dating business.’

      The words had come out of her like a dam burst, but Darren caught every last drop, and mopped them up and dealt with them like he mopped the tears from her cheeks. She didn’t even need to tell him where to find the tissues. Was it just a performance for her benefit? To persuade her to let him see more of the kids, or to soften her up for whatever he and Lauren were planning next? She felt she ought to be more cynical, but she was too exhausted and wrung out to do anything but accept the sympathy on offer.

      Her friends were far away and had their own worries. They’d all drifted apart since they started having families – literally as well as metaphorically, as they had moved out in different directions to various London suburbs. She missed the gossip and the laughter, but Darren had always been her emotional anchor. In her twenties, she’d provided the shoulder to cry on as her friends went through dating disasters and