‘Say it.’

Ellie demands I speak for a second time. Her voice is firm and calm – but it’s that unruffled tone that terrifies me. This is the teenage Ellie, the one who’d lead the way clambering up the paddles outside, trying to get to the top of the waterwheel. She’s mellowed over the years because that’s what time does to people. What was once important gradually becomes just another thing.

Except Ellie lost a brother, a twin brother. How can that ever become ‘just another thing’?

‘I was driving.’

My words are almost lost to the sound of the river outside. Nothing happens for a moment.

It was so long ago that there are times where I’ve convinced myself it’s not true. The reality is that Wayne was driving. Everyone knows that. It happened. It’s only when I let my mind wander that the truth appears.

‘Louder.’

I shout this time, finally saying what I should have done so many years ago. ‘I was driving.’

As if to confirm it, the scar around my temple throbs and there’s a stabbing pain in my ribs. I was never the same after the crash and I suppose the physical changes pale compared to everything else.

‘Louder.’

‘I WAS DRIVING!’

The only other sounds are the river and the gentle wheeze of Tyler trying to breathe at my side. Ellie takes a step forward, her silhouette swelling in the spotlight.

‘That car was his pride and joy,’ she says.

‘Yes.’

‘He was a sensible driver.’

‘Yes.’

‘I’d been in the car with him, we all had. He was careful. He didn’t speed. He didn’t like taking risks.’

‘I know.’

‘So why would he have been showing off? You were driving.’

‘Yes.’

The way she spells it out now is so matter-of-fact, so obvious, that I can’t believe nobody ever questioned things.

‘You switched places,’ she adds. ‘You belted yourself into the passenger seat and put him behind the wheel. You dragged his dead body into the driver’s seat after you killed him.’

I’m silent at that. I haven’t thought about those moments in a long time.

Actually, that’s not true. It’s strange in that I seem to always think about it and yet it’s a memory that sits behind other thoughts. It’s like a fingernail; always there and yet hardly noticeable.

‘I didn’t mean to,’ I say.

‘Tell me what you did.’

‘Ell—’

‘Tell me!’

‘Where’s Olivia?’

‘Tell me, or I swear to God...’

She doesn’t finish the sentence but she doesn’t need to. What choice do I have? I can see what she has done to Tyler.

‘Why him?’ she asks.

‘I don’t know what you mean.’

‘Why did he die and you survive?’

Ellie is choked, the words sticking in her throat.

‘I don’t know,’ I reply. ‘Luck. That’s all I can say. I remember opening my eyes. My chest and eye hurt but I felt okay. Then I looked across and saw him in the passenger seat and he… wasn’t. I don’t have a better explanation. When I said at the graveyard that I sometimes wish it was me who died, I meant it.’

‘What happened then?’

Tyler wobbles, his head lolling to the side. I try to prop him up but Ellie hisses for me to leave him. All I can do is lean him against the wall.

‘I didn’t plan it,’ I say. ‘It was impulse… instinct to move him. After I’d done it, I was going to put him back but then I heard the other car pulling in.’

‘Your Angel David?’

I shiver at the memory. ‘Right. There was no turning back. I wanted to tell people but it was too late. It was Wayne’s car and he was in the driving seat. Everyone assumed he was driving.’

‘You made them assume.’

‘I know. I’m sorry.’

The shadow of the knife rises and, though she’s across the floor, there’s a moment in which I think Ellie is going to leap forward. Even over the noise of the river, I hear her take a breath. Her silhouette hulks larger and then softens.

‘It wasn’t enough for you, was it?’ she says.

‘What wasn’t?’

‘You couldn’t stop at ruining one of my brothers, you had to have the other.’

There’s a lump in my throat. Self-serving, I know. How can I feel sorry for myself after what I did? She’s right to hate me.

‘I didn’t plan that,’ I say.

‘You knew Jason adored you.’

‘Yes.’

‘And you led him on.’

‘I…’

I stumble, because I don’t have the words – and she wouldn’t want to hear them anyway. I didn’t lead Jason on as such but I didn’t discourage him. Of course I knew he had a thing for me. Everyone did. The kids at school knew. Wayne knew. Ellie knew. He was a couple of years below us but he’d follow his brother and sister around to spend time with me. If I lay on the riverbank, he’d lay at my side. If I tried to wade into the river, he’d follow. When we were fourteen or fifteen and he was eighteen months younger, it was funny to see what he’d do for me. By the time I was nineteen and he’d recently turned eighteen, things were different. It definitely wasn’t funny any longer.

‘I shouldn’t have let it happen,’ I say.

‘But you did – and then you broke his heart.’

‘I was young, Ell. We were young. I didn’t know what would happen after I broke up with him. I’m sorry.’

‘Oh, you will be.’

She spits her reply with righteous fury.

‘What do you mean?’

‘You took my brother – my brothers – and I’m going to take your daughter.’

I scramble to my feet. The sawdust and sand scuffs underneath. My knees wobble because I’ve been sitting on them for too long.

‘Stay where you are,’ Ellie says.

‘Where’s Liv?’

‘Sleeping. She had a rather strong sedative with her can of Coke during her accounting lesson. You know I can’t have children. I was doing all that for your daughter after what you’d done to me?’

She’s right. How can I ever justify it?

‘I never meant for everything to happen,’ I say.

‘But you never spoke up about it, did you? You let everyone believe Wayne was driving when it was you. It took me crashing my own car to realise.’

‘I’m sorry.’

‘Stop saying that!’ She speaks through clenched teeth. ‘It’s always about you, isn’t it? You’re obsessed with yourself; always whining about your husband. You know the problem isn’t Dan, don’t you? It’s you.’

Her words hurt because they scratch at my darkest fears. She’s only saying what I’ve laid awake thinking about. Life is so easy when everything’s an injustice. If it’s someone else’s fault, then every day is a challenge to prove a point. Without that, a person can only wallow in failure.

‘I don’t know how he put up with you this long,’ Ellie adds. ‘And then, after everything you have – a successful, smart husband; a daughter – after all that, you’re getting a divorce! It’s always, always, about you.’

I don’t argue. She’s right. How many conversations have we had about her problems over the years? I’ve accepted that she lives alone, never asking if she craves more. We haven’t had a conversation about whether she wants to have children, or how the removal of her ovaries has affected her life. I wondered if she was falling into depression because she rarely left the house – but I never actually asked and I didn’t offer to go places with her. It is always about me. I scoff at someone like Natasha for the mundanity of her life – but mine is a constant invented drama. All the arguments with Dan and Olivia over nothing – and for what?

‘What are you going to do?’ I ask, not sure I want the answer.

Ellie replies with mortifying calm: ‘I’ll tell the police Olivia has been confiding in me during our classes. She was scared of what her mum might do. Her dad’s leaving and her mum fears she can’t afford to be by herself. Her mother’s been arguing with her boyfriend and making threats. She’s been saying, “we’ll always have each other”, and things like that.’

It’s more or less true.

‘People love to believe others are crazy,’ Ellie adds. ‘They say, “You’re mad”, “You’re mental”, “You’re not right in the head” – all that. Look at how erratic you’ve been all week. Not hard to believe you’re going off the rails.’

There’s a horrible, creeping realisation that she’s right. What’s going to happen if the police talk to Peter the receptionist, or Stephen? Or Graham from work? Or Declan? Or Dan himself? All of them will confirm how unpredictable I’ve been. There’s a pattern. I presume Ellie’s orchestrated much of it but that won’t matter.

‘What are you going to do?’ I ask again.

‘Wait and see.’

‘Is Liv here?’

‘Wouldn’t you like to know?’

Tyler mumbles something and I turn to look at him as he slides to the floor. I want to help but I’m not sure what I can do.

‘What did you do to him?’ I ask.

‘He was a late addition. Bit of an accident, really. He’s dropped around a couple of times to pick up Liv after her class. Always seemed like a good kid to me – not that you thought so. You always see the worst in people. He was stomping down the road looking angry the other night. I asked if he was all right and he said you’d been on at him. I asked if he wanted a smoke or drink back at mine. Quick couple of dissolvable painkillers in his beer and out he went. I told you they knock me right out. They did the same for him.’ She pauses and I can imagine her licking her lips. ‘…And Liv.’

She said Olivia was sleeping and I can only hope it’s true and nothing more. I wonder if I can get to Ellie, perhaps wrestle the knife away. The moment I take a step forward, the sandy dust crunches underfoot.

Ellie tells me to stop and I do. Any movements I make are a giveaway. I’m stuck in the corner next to Tyler until she decides otherwise.

‘Have you had Tyler here the whole time?’ I ask.

‘Course not. He was in my basement most of the time. Heavier than he looks, mind. Getting him up the stairs and into the rental car was hard work.’

‘That’s how you got his blood?’

‘Obviously. For a while I hoped the police might latch on. Find the blood on your car, then I realised you’d done a good job cleaning. Had to leave a little more.’

I suppose that explains the little things around the house. Keys being moved, a faked break-in, the missing money. All little bits and pieces to keep me on edge. Ellie waited for me to leave the house and then used her keys to get in and out.

‘I told Tyler I’d kill Olivia if he tried to escape,’ Ellie says. ‘He really does care for her. He’s been as good as gold all week. I guess the sedatives help, but still… Good job the doctor was so happy to dish out the prescription. I was only turning it on a bit to try to get a whiplash claim in. Didn’t realise he’d give me more drugs than a Colombian war lord.’

‘What did you mean when you said you were going to take Liv?’

‘What do you think?’

‘She’s not dead…?’

Ellie lets it hang, taking a while to reply. ‘I’m not going to do anything,’ she says. ‘You’ve already done it. Going off the rails, remember? Erratic. Unpredictable.’

It suddenly dawns properly that it’s her aim to pin on me whatever she has planned for Olivia and Tyler.

I shiver, my words trembling as well: ‘People won’t believe I did any of this.’

‘Really? Not even after Olivia texts her father to say you’ve been acting really weird? That she’s worried about what you might do? Not after your many arguments with Tyler? All the rows with Dan? The blood in the garage? You don’t think that perhaps there’s a speck of blood you might have missed in your car? Did you find his chain? After all that, you don’t think people will believe you could do any of this…?’

She’s right. She was right before that people are desperate to believe others are mad and she’s right about this. I’ve left a trail of destruction around me for seven days and it’s all too easy to believe I’ve lost it.

‘Were you at the hotel?’ I ask.

‘I didn’t think you’d make it so easy. Simply enough to invent Luke and set up an email and website. Suggest a hotel. Took me less than an hour. Keeping track of mobile phones was a nuisance, though. I almost texted you from the wrong one. After that, it wasn’t hard to persuade someone to slip something into your drink. Expensive but easy. There was something cathartic about driving you out to the middle of nowhere and then dragging you into the driver’s seat. The whole time, I was thinking about how you’d done exactly that to my brother. I wondered if it might trigger some memories. A bit of guilt for once. Perhaps you’d own up to your own actions, instead of blaming others?’

I’m silent but I slide myself forward a couple of steps without raising my feet. It’s the only way I can manage to move without making a noise. I can only see Ellie’s shadow but, if she’s in the dark, that means she can’t see much of me either.

‘What I didn’t expect,’ she adds, ‘is that you’d be suspicious of so many other people. You’re so self-centred. It’s been hilarious watching you this week. You even ran over wanting to borrow my car. What is wrong with you?’

I suppose she has me there. Something is wrong with me. There has to be. I leave carnage in my wake. Look at Dan. He’s intelligent with a good job. We’ve created a talented, smart young woman in Olivia – and yet I’ve spent years arguing with both of them.

‘Why go through all the effort?’ I ask. ‘The hotel, the car, the house, Tyler…’

‘Because I wanted you to feel a fraction of the confusion, the anger, the pain, I’ve had of being by myself for twenty years – all because of you.’

Ellie’s shouting now, drowning out the roar of the river with the snarl of her voice.

‘You can’t know what it’s like to have a twin, to share a womb, and have that ripped away. At least you’ll get to feel some of that now.’

‘Where’s Olivia?’

Ellie has crescendoed to a peak of fury but when she speaks next, she’s measured once more – and terrifyingly direct. ‘She’s already dead.’