I’m shaking, I’m so angry. ‘You don’t get it, do you?’ she says. ‘I didn’t realise, you have absolutely no idea about your mother. No idea at al !’

She stares at me, faux concern on her face. ‘Oh, Natasha.’

‘What do you mean?’ I say. ‘You al right in the back there?’ Mike cal s to us.

We freeze. ‘Oh, yes!’ Octavia says quickly, smilingly, and then she turns to me, lowers her voice, and hisses, ‘ Do you really not know the truth about her? ’

Her face is right next to mine. I shake my head, trying to look unconcerned.

‘Whatever, Octavia. I’m not interested.’

Octavia’s face is pale, so close to mine. I can see her open pores, the down of hair on her cheek, smel her warm breath on my skin. Her voice is sing-songy. She says softly, ‘She kil ed her sister, Natasha. That summer.’

At first I think I’ve misunderstood what she’s saying, and I listen to the words again in my head. ‘No,’ I say, after a few moments. ‘That’s not true.’

Moonlight flickers into the car through the branches of the trees, as if a light is being turned on and off. I blink.

‘Think about it,’ Octavia says. ‘Haven’t you always known something strange happened?’ And then she’s silent, watching me, as I furiously shake my head. ‘Look, I’m sorry,’ she says, after a pause, as though she knows she’s gone too far. ‘I didn’t mean to—’

‘I knew you were talking rubbish anyway,’ I say, thinking she’s apologising, that she’s made it up to hurt me, but she says, ‘I didn’t mean for you to find out like this. I thought you must know by now.’

This family’s poisoned. The diary’s in my pocket. ‘I don’t think she planned it out,’ Octavia says. ‘It’s not like she poisoned her or anything.’ Her voice is almost pleading, as though she wants me to be OK, as though she feels bad. ‘But – you know, they had a row about something – I don’t know what it was. I don’t think Mum knows. They had a blazing row and Miranda pushed Cecily, and she slipped on the path and broke her neck.

That’s what happened. Archie saw them. Ask – ask Guy,’ Octavia says suddenly, wiping her nose with her hand, very unlike her. ‘He knows it al .

Your mother tried to seduce him. She tried to seduce my father, too.’

‘Look, this is just so stupid –’ I say. She ignores me. ‘Wel , he saw straight through her, they both did. That’s why no one likes her.’ She gets out a tissue and blows her nose. ‘That’s what the row was about.’ She sniffs loudly. ‘Everyone knows what your mother did, but they didn’t want to upset your grandmother. They weren’t even al owed to mention Cecily in front of her, were they?’ I nod. We weren’t – it was the only rule at Summercove.

‘But now Great-Aunt Frances is dead, wel – things have changed, haven’t they?’

The bubble is burst. It’s cold in the cab and I squeeze my arms to my side. ‘I – I just don’t believe you.’

‘Have you ever thought that explains quite a lot about her?’

‘No,’ I say. ‘Absolutely not. And frankly, Octavia—’

‘Maybe she didn’t plan it, but she kil ed her al the same. Ask Guy. He was there,’ Octavia says again, flatly.

‘That’s such crap – how the hel do you know that’s what happened?’ I sit up, ful of righteous anger. ‘How do they know? Why hasn’t anyone ever said anything to me about it before? Why hasn’t Mum ever said—’

‘She’s not going to, is she?’ Octavia says, genuinely pitying. ‘But your mother – oh, I don’t know what was going on that summer,’ she says.

She scratches her forehead. ‘I don’t think Mum knows, even. Just – al I’m saying is, your mother wouldn’t tel anyone what the row was about, and there’s no way of finding out, is there?’

‘No,’ I say, and I think of the diary again, and then remember how thin the outline of it feels between my fingers, how childish. But I don’t touch it again. I don’t want Octavia suspecting anything. I look at her, and think how strange it is that I know her real y wel , and yet I don’t know her at al .

Never been to her house, don’t know any of her friends, or about her romantic life, or her favourite books to read or anything. She’s just always been there. I thought we were family, and it turns out I don’t know her at al either.

She’s right. I’ve been living in a dreamworld. ‘Look,’ she says, as though she’s regretting speaking so hastily. ‘I hope – I’m sorry, perhaps I shouldn’t have said anything.’ She clears her throat. ‘But you had to know. I can’t believe you’ve never heard an inkling of it before.’

There’s a lot I could say to this, but I don’t. I raise my hand. ‘It’s OK. Look, let’s just not talk about it any more.’

We slide into an awkward silence for the rest of the journey, but I’m glad. I don’t know what on earth we’d talk about.

Chapter Eleven

The sleeper train from Penzance has a special platform to itself, outside the main station. I like that; it accords it a proper position. In summer, it can be a trying experience. It is always crowded, frequently extremely hot (the air conditioning is temperamental), and it gets light so early that, as a child, I would wake at three-thirty and never be able to get back to sleep, lying there on the top bunk under the scratchy blue blankets, tossed about by the motion of the train.

Mum would come down again at the end of the summer to take me back to London, unless Granny was coming up herself, and I always hated it when Mum arrived because I hated leaving Summercove. It was like leaving a fairytale palace behind, a warm, airy, sweet-smel ing palace where I was free, where my grandmother was always there so I never got lonely, and where the sun shone and Jay and I were together. Back in London we knew September would be racing to catch us, damp-drenched mornings when the sun rose later and colder, and winter lay just around the corner, putting me and especial y my mother into a funk that would last til spring.

On the train back I would always go over the holiday in my head, committing it al to memory. The walk to Logan’s Rock, and the terrifying winds that threaten to blow you off to the treacherous waters beneath. Sitting outside at the Minack Theatre, an amphitheatre carved into the cliffs, screaming with laughter at A Midsummer Night’s Dream. Jay and I clambering down through the rocks to the beach below the house; the astonishing green and blue of the water, the ginger beer that was sharp and sweet, at the same time, on your tongue. The warmth, the wet, the wildness, the knowledge that being in Cornwal is like being in a different country, and that every mile you draw away from it is like leaving a part of you behind. Yes, I thought it was like something out of a fairytale.

After we’ve paid Mike and waved him off, Octavia and I stand on the blustery quayside, at the entrance to the station.

‘Do you know what carriage you are?’ I ask, my tone almost formal.

She shakes her head. ‘I have to go and pick my tickets up from the machine.’

‘Oh,’ I say. ‘Right.’

We are silent. I look down at my black boots. I pul ed them on this morning, at five-thirty, in the dark. It seems like a lifetime ago.

‘So, I’ve already got my ticket,’ I say, waving the orange card at her. ‘I think I’l —’

‘Yes, yes,’ she says, a touch too eagerly. ‘Wel , it was . . .’ she trails off. ‘Er, good to see you.’

Someone hurries past us, dragging a suitcase on wheels. It crackles loudly over the tarmac. ‘Look, Natasha,’ Octavia says, after another silence. ‘I’m sorry. Perhaps I shouldn’t have said it like that.’ She holds her hands up. Don’t blame me. ‘I just thought you’d have heard. You know, everyone’s always . . .’ She trails off again, and crosses her arms defensively. ‘It’s al water under the bridge, I suppose.’

‘It’s clearly not though, is it?’ I say. ‘It’s anything but that. It explains a lot, anyway.’ I’m trying not to sound angry. ‘Look, your mum’s always had it in for my mum and I’ve never known why, and now I do. That’s why I’m not surprised.’

‘You understand why now.’ Octavia nods, as if to say, Good. She’s final y getting it.

‘No, I don’t believe it, Octavia. What I mean is,’ I say, breathing deeply, ‘I understand why you’ve always been so vile to us now. I mean, did your mother tel you this herself?’

‘Not in so many words,’ Octavia says. ‘You don’t sit down and explain something like that – we just always knew. Dad, too. And Uncle Jeremy.

That’s why he never comes back.’ She shrugs.

‘Wel , as you like. I don’t believe for a second, a second –’ and I raise my voice so I’m speaking as loudly as possible without shouting, and I can hear myself, high above the clinking masts in the harbour, above the train engine – ‘that my mother kil ed Cecily, or anyone. I don’t know what happened, but I know that much.’ I sling my bag over my shoulder.

‘Hey –’ she begins. ‘That’s just what they say. I’m just saying—’

‘No,’ I interrupt. ‘Let’s not go into it again, OK? I think I’m going to get on, now. See you around then. Thanks for—‘ I don’t know what to thank her for, but since I’ve started I think I’d better finish. ‘Er – thanks for sharing the taxi fare with me.’

Octavia nods back – what else can she do? – and says, ‘No problem.’

I don’t look back at her as I walk towards the train. I pray I don’t bump into her again, but I’m pretty sure she’l steer clear of me this time. She thinks she’s done me a favour. That’s what upsets me most of al . Pointed out how stupid I’ve been.

In the summer the buffet car is always ful ; people arrive as early as possible to get a seat so they’re not shut into their cabins, which are initial y cute but soon become claustrophobic. In winter, the car is nearly empty, and after I have dumped my bag in the single-bed cabin and admired the free set of toiletries, I settle down into one of the single seats by the window, with a table and a lamp, and put my bag in front of me. I look around hastily again, but Octavia hasn’t appeared. The diary pages are stil in my pocket. I sit there, and the train pul s slowly away from the station, and I don’t know what to feel.