‘We?’ Naomi spluttered. ‘We, Max? It all happened because of you. You got us into it and you’re the one who made us leave him there.’

‘You’re lying. We all agreed at the time,’ he said.

‘I was in shock. I was scared.’

‘Naomi?’ Pip said.

‘We . . . um, we went out to that crappy little club in Amersham,’ she said.

‘The Imperial Vault?’

‘Yeah. And we had all had a lot to drink. And when the club closed it was impossible to get a taxi; we were like seventieth in the queue and it was freezing outside. So Max, who’d driven us all there, he said that actually he hadn’t drunk that much and was OK to drive. And he convinced me, Millie and Jake to get in the car with him. It was so stupid. Oh god, if I could go back and change one thing in my life, it would be that moment . . .’ She trailed off.

‘Sal wasn’t there?’ Pip asked.

‘No,’ she said. ‘I wish he had been because he’d never have let us be that stupid. He was with his brother that night. So Max, who was just as drunk as the rest of us, he was driving too fast up the A413. It was like four o’ clock and there were no other cars on the road. And then –’ the tears came again – ‘and then . . .’

‘This man comes out of nowhere,’ Max said.

‘No, he didn’t. He was standing well back on the shoulder, Max. I remember you losing control of the car.’

‘Well, then we remember very differently,’ Max snapped defensively. ‘We hit him and spun. When we came to a stop I pulled off the road and we went to see what had happened.’

‘Oh god, there was so much blood,’ Naomi cried. ‘And his legs were bent out all wrong.’

‘He looked dead, OK?’ Max said. ‘We checked to see if he was breathing and we thought he wasn’t. We decided it was too late for him, too late to call an ambulance. And because we’d all been drinking, we knew how much trouble we’d be in. Criminal charges, prison. So we all agreed and we left.’

‘Max made us,’ Naomi said. ‘You got inside our heads and scared us into agreeing, because you knew you were the one really in trouble.’

‘We all agreed, Naomi, all four of us,’ Max shouted, a red flush creeping to the surface of his face. ‘We drove back to mine ’cause my parents were in Dubai. We cleaned off the car and then crashed it again into the tree just before my driveway. My parents never suspected a thing and got me a new one a few weeks later.’

Cara was now crying too, wiping the tears before Naomi could see them.

‘Did the man die?’ Pip said.

Naomi shook her head. ‘He was in a coma for a few weeks, but he pulled through. But . . . but . . .’ Naomi’s face creased in agony. ‘He’s paraplegic. He’s in a wheelchair. We did that to him. We should never have left him.’

They all listened as Naomi cried, struggling to suck in air between the tears.

‘Somehow,’ Max eventually said, ‘someone knew what we had done. They said that if we didn’t do everything they asked, they would tell the police what we did to that man. So we did it. We deleted the pictures and we lied to the police.’

‘But how could someone have found out about your hit-and-run?’ said Pip.

‘We don’t know,’ Naomi said. ‘We all swore to never tell anyone, ever. And I never did.’

‘Me neither,’ Max said.

Naomi looked over at him with a weepy scoff.

‘What?’ he stared back at her.

‘Me, Jake and Millie have always thought you were the one who let it slip.’

‘Oh, really?’ he spat.

‘Well, you’re the one who used to get completely plastered almost every night.’

‘I never told anyone,’ he said, turning back to Pip now. ‘I have no idea how someone found out.’

‘There’s a pattern of you letting things slip,’ said Pip. ‘Naomi, Max accidentally told me you were M.I.A. for a while the night Andie disappeared. Where were you? I want the truth.’

‘I was with Sal,’ she said. ‘He wanted to talk to me upstairs, alone. About Andie. He was angry at her about something she’d done; he wouldn’t say what. He told me she was a different person when it was just the two of them, but he could no longer ignore the way she treated other people. He decided that night that he was going to end things with her. And he seemed . . . almost relieved after he came to that decision.’

‘So let’s be clear,’ Pip said. ‘Sal was with you all at Max’s until twelve fifteen the night Andie disappeared. On the Monday, someone threatens you to go to the police and say he left at ten thirty and to delete all trace of him from that night. The next day Sal disappears and is found dead in the woods. You know what this means, don’t you?’

Max looked down, picking at the skin around his thumbs. Naomi covered her face again.

‘Sal was innocent.’

‘We don’t know that for sure,’ Max said.

‘Sal was innocent. Someone killed Andie and then they killed Sal, after making sure he’d look guilty beyond reasonable doubt. Your best friend was innocent, and you’ve all known it for five years.’

‘I’m sorry,’ Naomi wept. ‘I’m so, so sorry. We didn’t know what else to do. We were in too deep. We never thought that Sal would end up dead. We thought if we just played along, the police would catch whoever had hurt Andie, Sal would be cleared and we’d all be OK. We told ourselves it was just a small lie at the time. But we know now what we did.’