‘Aren’t you – can’t you stop him?’ Fatima asked Ambrose, her eyes wide with disbelief. Ambrose winced as the sound of broken glass came from above, and then shook his head.

‘I would if I could, but there’s some kinds of pain that only stop hurting when you lash out. Maybe this is what he needs to do. I just wish …’ He rubbed his face, and suddenly he looked every day his age. ‘I just wish he wasn’t breaking up his own stuff. God knows, he’s not got much. He’s hurting himself more than me. What happened in that pub?’

‘He took it, Dad,’ Kate said. Her face was white with upset. ‘He really did. You know what they’re like, it’s that kid, Ryan or Roland or whatever his name is. The big one with the dark hair. He’s always had it in for him. But Luc was putting up with it really well, he was just laughing it off. But then Ryan, he said something else, and Luc – he just lost it.’

‘What did he say?’ Ambrose asked, leaning forward in his armchair, but for the first time I saw the shutter come down between Kate and her father. She went completely still, a kind of wary reserve behind the blank mask of her face.

‘I don’t know,’ was all she said, her voice suddenly flat and strange. ‘I didn’t hear.’

Ambrose didn’t punish Luc, and Fatima shook her head over it on the way home because we all knew, relaxed though he was, that he would never have tolerated that kind of behaviour from Kate. There would have been recriminations, reproaches, repairs taken out of her allowance.

With Luc though, Ambrose seemed to be an unfailing well of patience. And now I understand why.

Freya is asleep, her breathing even and feather-light, and I stand, stretching, lost in memories as I stare out across the estuary towards Salten, remembering the Luc I knew, before we went away, and trying to work out why his anger in the post office has shaken me so much.

I knew that that fury was there, after all. I’d seen it, directed at others, sometimes even at himself. And then I realise. It’s not his anger that has scared me. It’s seeing him angry at us.

For back then, no matter how furious he was, he treated the four of us like bone china, like something too precious to be touched, almost. And God knows, I wanted it – I wanted to be touched, so very much. I remember lying beside him on the jetty, the heat of the sun on our backs, and turning to look at his face, his eyes closed, and longing with a heat so fierce that I thought it might consume me, longing for him to open his eyes, and reach out towards me.

But he did not. And so, with my heart beating in my chest so hard that I thought he could surely hear it, I reached out and put my lips to his.

Whatever I expected to happen, it was not this.

His eyes flew open instantly, and he shoved me away, crying out, ‘Ne me touche pas!’ scrambling up and back so hard he almost fell into the water, his chest rising and falling, his eyes wild, as if I’d ambushed him while sleeping.

I felt my face turn scarlet, as if the sun were burning me alive, and I got up too, taking an involuntary step back, away from his furious incomprehension.

‘I’m sorry,’ I managed. ‘Luc?’

He said nothing, just looked around, as if trying to understand where he was, and what had happened. In that moment, it was almost as if he didn’t recognise me, and he looked at me as if I was a stranger. And then recognition came back into his eyes, and with it a kind of shame. He turned on his heel, and he ran, ignoring my cry of ‘Luc! Luc, I’m sorry!’

I didn’t understand then. I didn’t understand what I had done wrong, or how he could react so violently to what was, after all, barely more than the sisterly kiss I’d given him a hundred times.

Now, though … now I think I know what kind of experiences were at the back of that terrified reaction, and my heart is breaking for him. But I am wary, too, for that moment gave me a taste of what I felt again in the post office.

I know what it’s like to be Luc’s enemy. I have seen him lash out.

And I can’t help thinking of the dead sheep, of the fury and pain behind that act, of its guts spilling out like festering secrets into the clear blue water.

And now, I am afraid.

‘WHAT ARE YOU going to do?’ Fatima says in a low voice, handing me a cracked porcelain cup.

Lunch is over. Fatima and I are washing up – or rather she’s washing, I’m drying. Freya is playing on the hearthrug.

Kate and Thea have gone out for a cigarette, and to walk Shadow, and I can see them through the window, walking slowly back along the bank of the Reach, heads bent in conversation, the smoke from their cigarettes dispersing in the summer air. It’s odd, they’re walking the other way to the route I would have gone – north towards the main road to Salten, rather than south to the shore. It’s not nearly as nice a walk.

‘I don’t know.’ I wipe the cup and set it on the table. ‘How about you?’

‘I – I honestly don’t know either. All my instincts are shouting at me to go home, it’s not like we can change anything by being here, and at least in London we’re less likely to get a knock on the door from the police.’

Her words give me a shiver, and I glance involuntarily at the door, imagining Mark Wren walking across the narrow bridge, knocking on the blackened wood … I try to imagine what I would say. I remember Kate’s vehement injunction last night – We know nothing. We saw nothing. That has been the script for seventeen years. If we all stick to it, there is nothing they can do to prove otherwise, surely?

‘I mean, I want to support Kate,’ Fatima continues. She puts down the sponge and pushes back her scarf, leaving a smudge of white foam on her cheek. ‘But a school reunion when we’ve never been to one before? Is that really a good idea?’

‘I know.’ I put another cup on the table. ‘I don’t want to go either. But it’ll look worse if we bail out at the last minute.’

‘I know. I know all that. Rule two – stick to your story. I mean I get it, I do. For better or worse, she’s bought the bloody tickets and told everyone that’s why we’re coming down, so I can see it’s better to see it through. But that thing with the sheep …’

She shakes her head and returns to washing the lunch things. I sneak a quick glance at her face as she scrubs.

‘What was that about? You saw the body better than I did. Was it really Shadow?’

Fatima shakes her head again.

‘I don’t know,’ she says. ‘I’ve only seen a couple of dog attacks, and maybe it’s different when they attack people, but it didn’t look …’

My stomach clenches, and I’m not sure if I should come clean. If the police get involved then perhaps it’s better if Fatima doesn’t know, doesn’t have anything to conceal, but we swore never to lie to each other, didn’t we? And this is lying of a kind – a lie by omission.

‘There was a note,’ I say at last. ‘Kate saw it, but she hid it in her pocket. I found it when I went to rinse her coat.’

‘What?’ Fatima looks up at that, her face alarmed. She drops the dishcloth and turns to face me. ‘Why didn’t you tell us?’

‘Because I didn’t want to worry you. And I didn’t want …’

‘What did it say?’

‘It said …’ I swallow. The words are almost unbearable to speak, and I have to force myself to make them real. ‘It said, Why don’t you throw this one in the Reach too?’

There is a crack, as Fatima drops the cup she is holding, and all the colour and expression drains from her face, leaving it a pale Noh mask of horror, framed by her dark headscarf.

‘What did you say?’ Her voice is a croak.

But I can’t bring myself to repeat it again, and I know full well she heard me, she is just too scared to admit what I already realise – that someone knows, and is bent on punishing us for what happened.

‘No.’ She is shaking her head. ‘No. It’s not possible.’

I put down the tea towel, and go to the sofa where Freya is playing, and I slump down, my face in my hands.

‘This changes everything,’ Fatima says urgently. ‘We have to leave, Isa. We have to leave now.’