My mouth fell open, but Luke stepped forwards before I could speak.
‘Listen to yourself, Mason. You’re talking shit! Saying one thing and then the other, just like Cora said.’ He made a move as though to seize the bottle, but Mason took a step back.
‘That’s because I don’t know what happened!’ he said, with something between anger and desperation. ‘I don’t know who I can trust! For all I know, you killed Sadie.’
Even in the dark, I saw Luke’s face go purple. For a second, he looked as though he was going to hurl himself forwards, broken bottle or not. ‘Sadie’s my sister,’ he said. Not loudly. But in as frightening a voice as I’ve ever heard. ‘I’d sooner kill myself than hurt her.’
The bottle wavered in Mason’s hand, and for the first time I saw him show a flicker of doubt. But then he looked at me, Cora and Abi in turn, and his whole body seemed to tighten.
‘Do you want to hear something, Luke?’ he said. ‘Do you want to know why the police were so convinced it was me? Because they think Sadie was killed by someone she knew. Someone she trusted, who could have lured her out of the house. Which, yeah, puts me in the frame, but also applies to every single one of them.’ This time he swung the bottle in an arc. Without any of us realising, I think, me, Cora and Abi had clustered together. ‘And there was something else … something they found in Sadie’s bedroom. Something anybody here could have planted.’
I had no idea what he was talking about, but even so, I felt the bottom drop out of my stomach.
‘They found a test. Hidden away in her stuff. A pregnancy test.’
All at once inside the cave there was a silence, so heavy that for a moment it drowned out the rain.
‘Sadie was pregnant?’ said Cora, in shock, or horror, or both.
‘I didn’t say that,’ Mason hissed at her. ‘I said they found a test. Half a one. A two-pack, with one of the thingamajigs missing. To make it look like Sadie was pregnant. Which gave the police the one part of the case against me they were missing. It gave them motive. They think I wanted Sadie to get rid of it, or to keep it, or whatever she didn’t want to do.’
Even Luke shrank backwards as he tried to process what he was hearing. Me, I couldn’t have said anything if I’d wanted to.
‘But the thing is, me and Sadie were careful,’ said Mason. ‘Always. There’s no way she would have had a pregnancy test. She wouldn’t ever have needed one. So what I want to know,’ he went on, holding up the bottle again, ‘is the answer to the question I asked at the beginning. Which one of you did it? And which one of you tried to trick the police into thinking it was me?’
I looked at Luke, hoping that if anyone could get through to Mason, he could. But Luke seemed almost to have shut down. His mouth was hanging open, and his eyes were focused on the floor. Abi was no help either. She was staring at Mason, shaking her head uselessly.
‘Mason, listen to me,’ said Cora. ‘Nobody tried to frame you. I swear it. We’re your friends. We’re Sadie’s friends. We would never have tried to hurt either one of you!’
‘So where were you, Cora?’ said Mason. ‘If you’re my friends, how come I didn’t hear from any one of you after Sadie went missing? Even you, Fash. I had to come to you to ask for help, remember?’
To trick me, he meant. To use me.
But on the other hand, I guess he had a point. I mean, I could only imagine how he must have felt. How it might have seemed like we’d turned our backs on him. But it wasn’t that. Not for me, anyway. The truth is, there was another reason I was staying away. The same reason that, when Mason came to me, I agreed to do what he asked.
‘Maybe I didn’t come to see you,’ said Cora, ‘but I tried to help you. I did. I just, it didn’t …’ She was looking at Luke as she spoke, but before she could explain any further, there was movement in the shadows outside. Even Mason noticed from the corner of his eye.
‘What the fuck was that?’ he said.
I looked at the others, to see if they’d seen it, too. Luke was frowning out into the darkness. Cora and Abi glanced at each other, as though … as though they were sharing something. You know? A thought, a realisation … something.
And then there was a noise, like someone running through the undergrowth, and Abi shrank back against the wall of the cave.
‘Oh shit,’ she was saying. ‘Oh shit, oh shit, oh shit …’
Luke darted forwards, but stopped when Mason swung the bottle.
‘Cut me if you want,’ said Luke, with the jagged glass centimetres from his face. ‘Go on. Do it. It’s the only way you’re going to stop me getting past you.’
And I guess he must have seen something in Mason’s eyes. Capitulation, hesitation, whatever you want to call it. And then Luke was moving again, out of the cave, across the stream and scrabbling up the bank.
‘Luke!’ yelled Cora. ‘Wait!’ She sounded afraid – even more afraid than she was of Mason, I guess, because she was suddenly running for the woods, too. And by this point I don’t think Mason knew what to do. In fact, in spite of the broken bottle, he looked about as terrified as any of us.
All of a sudden Abi started running
