‘Or someone murdered him,’ she says.

ON THE TUBE on the way home the facts seem to jostle and tumble inside my head, ordering and reordering, as though I could make sense of all this if only I shuffle the deck in a different way.

Accessory to murder. Maybe even a suspect myself if Fatima is right.

This changes everything, and I feel hot and cold at the realisation of what we may have blundered into. I feel angry – more than angry. Furious. Furious with Fatima and Thea for not being able to reassure me. Furious with myself for not working this out sooner. For seventeen years I have been pushing away thoughts of what we did that night. For seventeen years I have been not thinking of what happened, trying to bury the memories under a hundredweight of mundane, everyday worries and plans.

I should have thought about it.

I should have thought about it every day, questioned every angle. Because now that I have unpicked that one thread, the whole tapestry of the past is beginning to unravel.

The more I think back, the more certain I am that the drawings had surfaced only that morning, the morning after Ambrose’s death. I had spoken to Miss Weatherby the night before at supper, she had asked after my mother and my weekend plans. There was absolutely no hint of what was to come, no hint of the raw shock and fury we saw in her face the following day. She could have been a truly extraordinary dissembler – but why? There was no reason for the school to wait before confronting us. If Miss Weatherby had seen those pictures on Friday, she would have hauled us into her office that same day.

No, the conclusion was inescapable: the drawings turned up after Ambrose died.

But who? And almost as importantly, why?

Someone blackmailing him, who had finally followed through with their threat?

Or someone who had murdered him, trying to provide a motive for his suicide?

Or … was it possible … could Ambrose himself have possibly sent them, in a fit of remorse, before taking his fatal dose?

But I shake that idea off almost straight away. What Ambrose did in drawing us might have been wrong, legally and ethically, an abuse of his position as Fatima had said. He might even have come to feel that himself, with time.

But I am absolutely and utterly convinced that, whatever he was feeling, Ambrose would never have posted those drawings to the school. Not to save his own shame, but because he would never have put us through the kind of public humiliation that ensued, would never have put Kate through it. His affection, his love for us was too great, and one thing I know, as the Tube train rattles through the tunnel, the dusty wind warm in my face, he did love us, for Kate’s sake, and for our own.

So who then?

A blackmailer from the village, who came to the Mill one day and caught sight of something he thought he could use?

I want it to be true. Because the alternative … the alternative is almost unthinkable. Murder.

And then there are far fewer people with a motive.

Not Luc. He is the one person who lost most from Ambrose’s death. He lost his home, and his sister, and his adoptive father. He lost any security he had.

Not any of the villagers, at least not that I can see. They might have blackmailed him. But they have no reason to kill a man who was one of their own.

So who then? Who had access to the drawings, and access to Ambrose’s stash, and was in the house before he died?

I press my hands to my temples, trying not to think about that, and trying not to think about the last conversation we had, Fatima, Thea and I, as we walked to South Kensington Tube, sunglasses on against the fierce, bleaching summer sun.

‘Listen, there’s just one more thing …’ Thea said, and then she stopped, in the archway to the Tube station, putting her fingers to her mouth.

‘Stop biting your fingers,’ Fatima said, but with concern, not censure. ‘What? What is it?’

‘It – it’s about Kate. And Ambrose. Shit.’ She ran her fingers through her short hair, and her face was stiff with apprehension. ‘No. No, it doesn’t matter.’

‘You can’t say something like that and not tell us.’ I put out my hand to her arm. ‘Besides, it’s obviously eating you up. Spit it out, whatever it is. You’ll feel better. What do they say – a problem shared?’

‘Fuck that,’ Thea said brutally. ‘Much good it’s ever done us.’ Her face twisted and then she said, ‘Look, what I’m about to tell you – it’s not that I think – I don’t want you to think …’

She faltered, pinching the bridge of her nose beneath the sunglasses, but Fatima and I kept silent, sensing that only waiting would bring this confession out.

And at last she told us.

Ambrose had been planning to send Kate away. Right away. To a different boarding school.

He had told Thea just the weekend before, when he was very drunk. Kate, Fatima and I were swimming in the Reach, but Thea had stayed up in the Mill with Ambrose, as he drank red wine, and stared up at the vaulted ceiling, and tried to come to terms with a decision he did not want to make.

‘He was asking me about schools,’ Thea said. ‘What Salten was like, in comparison to the other places I’d been. Whether I thought changing so often had screwed me up. He was drunk, very drunk, and not making complete sense, but then he said something about the parent–child bond, and I had this horrible cold lurch in my stomach. He was talking about Kate.’

She takes a deep breath, as if even now the realisation shocks her.

‘I said, “Ambrose, don’t do this. You’ll break Kate’s heart.” He didn’t answer straight away, but at last he said, “I know. But I just … I can’t let it go on like this. It’s all wrong.”’

What can’t go on? Thea had questioned him, or tried to, but we others were coming back, and Ambrose had shaken his head, and taken his bottle of red wine and gone up the stairs to his studio, shutting the door, before the rest of us had come in from the Reach, wringing water out of our hair and laughing.

And all that night, and the rest of the week, Thea had looked at Kate wondering, does she know what he’s planning? Does she know?

And then Ambrose had died. And everything fell apart.

I can’t let it go on. Thea’s voice, echoing Ambrose, rings in my head as I walk back from the Tube station, hardly feeling the hot afternoon sun on the back of my head, I’m so preoccupied with my own thoughts.

It’s all wrong. What did he mean? I try to imagine what Kate could have done that would be bad enough for him to consider sending her away – but my imagination fails. He had watched Kate, all of us, stumble through that year making mistakes and questionable decisions, exploring drink and drugs and our sexuality. And he had said nothing. In a way it was no wonder, with his own past he had few stones left to cast. He only watched with love and tried to tell Kate and the rest of us when we were putting ourselves in danger, without judgement. The only time I can remember him getting really angry was over the pill Kate took at the disco.

Are you mad? he shouted, his hands in his wiry hair, making it stand up on end like a rats’ nest. Do you know what those things do to your body? What’s wrong with some nice healthy weed for crying out loud?!

But even then, he never grounded her, there was no punishment – just his disappointment and concern. He cared for her, for us. He wanted us to be OK. He shook his head when we smoked, looked on with sadness when Thea turned up with plasters and bandages over strange cuts and burns. When we asked him, he counselled, offered advice. But that was it. There was no condemnation, no moral outrage. He never made us feel wrong, or ashamed.

He loved us all. But more than anything, he loved Kate – loved her with an affection so fierce that it took my breath away sometimes. Perhaps it was the fact that it had been just the two of them for so long, after Kate’s mother died – but sometimes, there was something about the way he looked at her, the way he tucked her hair behind her ear, even the way he evoked her in sketches, as though he was trying … not to trap her exactly, but to pinpoint that quintessence that would enable him to preserve something of her forever on a page where it could never be taken away from him. It sang of an adoration that I glimpsed sometimes in my own parents, but dimly, as if through misted glass or far away. In Ambrose. though, it was a flame that burned fierce and bright.