The rest of the weekend seems accounted for. He was registered in various sessions and he was seen in those sessions throughout the weekend. But there is the tantalizing gap on Friday.

Webb points his finger. ‘Turn here.’

Moen turns off the highway and goes down a gravel road. It’s almost dark already. It’s been a miserable, wet day, but it’s warm and cosy in the car.

They’re returning to the scene where Amanda’s body was recovered. He’s been timing it since they left the resort. Moen is driving a bit too fast for the gravel road. ‘Slow down. We can estimate for speed later,’ Webb tells Moen. She lets up on the gas.

The way is dark and winding. The car’s headlights sweep around the bends in the road; trees rise on each side. Some of the trees are almost bare already; the weather has turned, and it seems much longer than a few days since they were out here, lifting the leaking car out of the cold lake.

‘Are you sure you’ll be able to recognize the spot in the dark?’ Moen asks, driving more slowly now. ‘I’m not sure I could. I’m a city girl.’

‘I hope so,’ Webb says, looking intently at the dark landscape beyond the windshield. ‘We’re getting close, I think. Slow down.’

She slows the car around a curve and he says, ‘Here. I think this is it. Pull over.’

He recognizes the curve in the road, the slope down to the beach, the edge of the lake. Moen pulls the car over and stops. She turns off the engine. Webb looks at his watch, glowing in the dark. ‘Twenty minutes.’

Moen looks at him, nodding. ‘No time at all.’

For a moment they sit in the dark, then they get out of the warm car into the chill of the night. Webb stands by the car door, getting his bearings, remembering the previous Monday morning when they’d made their gruesome discovery.

‘Where’s the murder weapon?’ Webb asks. He walks down to the edge of the water and looks out over the lake. A sliver of moon emerges sharp and bright from behind dark clouds. He tries to imagine what went on here. Who put the windows down? Whoever it was wore gloves, because there were no prints on the window buttons, other than Amanda’s. Who stuffed her body into the boot and guided the car down the slope and into the water?

Webb thinks the killer is quite likely someone they have already met. He turns to Moen; her eyes are glinting in the dark. ‘Whoever killed her was probably counting on her car – and her body – never being found at all,’ Webb suggests. He looks out again across the dark lake. ‘Everyone thought she’d left her husband. And it’s very hard to convict without a body.’ He glances again at Moen. ‘Somebody must be squirming. For somebody, this hasn’t gone according to plan.’

Becky hears the door downstairs open shortly after 9 p.m. She’s upstairs in bed, and cocks her head, listening. She’d grown tired of waiting for Larry and had eaten and gone up with a book. Now she listens to him wandering around downstairs. After a few minutes, she puts the book aside, pulls on her robe, and leaves the bedroom.

She stops at the top of the stairs when she sees her husband standing at the bottom, looking up at her. Their eyes meet, but neither of them speaks for a moment.

Then she says, ‘Where have you been?’ She doesn’t think he’s been at the office this late.

He doesn’t answer her. Finally Larry says, ‘We need to talk.’

She makes her way slowly down the stairs.

He says abruptly, ‘I need a drink.’ He slouches over to the bar cart in the living room and pours himself a stiff shot of bourbon.

‘You might as well pour me one, too,’ Becky says.

She walks over to him and he hands her a glass. They each take a sip. All the things he might say are swirling around in her head.

She wonders how Larry must have felt when Amanda disappeared – and then when her body was discovered. Was he worried that the police would find out about him and Amanda? The way she’d worried that they would find out about her and Robert?

He gives her a conciliatory look. ‘I had nothing to do with what happened to Amanda. And you know it.’

‘Do I?’ she says.

He stares at her, clearly shocked. ‘You can’t honestly think—’ He continues to stare at her, as if unable to find words.

‘I don’t know what to think,’ she says coldly. ‘And if I don’t quite believe you, how do you think the police are going to see it?’ As she stands there looking at him, this man she’s been married to for twenty-three years, she allows herself for the first time to actually consider whether Larry might have killed Amanda Pierce. It gives her a chill.

‘You can’t be serious!’ Then he laughs – a short, tight laugh. ‘Oh, I get it. You’re already in divorce negotiations, is that it? You feel you have some leverage over me and you want to use it to your advantage.’

She hadn’t really thought of it that way, but now that he’s mentioned it, she sees the possibilities. She doesn’t really believe that he harmed Amanda, but it wouldn’t hurt for him to think she does. She gave up her career. She spent her best years keeping house and raising children for this man, while he was out making a good living. She should get what’s coming to her. She doesn’t want to get shafted.

‘You absolute bitch,’ he says.

She jumps a bit at his tone. It’s so unlike him. Then she says, in a mild voice, ‘I’m not going to make things difficult for you, Larry, as long as you play fair with me.’

‘Is that so,’ he says. He comes closer and stares down at her; she can feel his breath in her face, smell the liquor. ‘I had nothing to do with Amanda’s … disappearance.’

It’s like he can’t say it. He can’t say death. She stands her ground. ‘But were you seeing her?’ Becky asks. ‘Tell me the truth. It wasn’t just that one time in your office, was it?’ She knows him. She knows he would want more. He can be greedy.

He slumps down onto the sofa and looks weary all of a sudden. His shoulders sag. ‘Yes,’ he admits. ‘We were seeing each other, for a few weeks. It started in July.’ He downs the rest of his drink in one long gulp.

She feels her entire body go cold. ‘Where?’

‘We went to a hotel on the highway outside of Aylesford.’

She stares at him in disbelief, swelling with incoherent rage. ‘You idiot,’ she whispers. ‘They’ll find out.’

‘No, they won’t,’ he says stubbornly, glancing up at her, and then shifting his eyes away again at the incredulous fury he sees there.

‘Of course they will! They’ll go around to all the hotels and motels with photos of the two of you and ask the staff!’ How can he think they won’t find out? She feels sick with fear now, and it makes her realize that she does care. People get arrested for things they didn’t do all the time. She cares enough not to want to see her husband dragged through a murder investigation. She can’t let that happen to her and the kids. She watched The Staircase on Netflix; she saw what that did to that family. It’s not going to happen to hers. She thinks rapidly. ‘Maybe you should have told the police when they were here. It’s going to be worse when they find out and you didn’t tell them.’