‘Oh.’ Lucy’s face has gone even pinker, and I am not sure if she is cross at her own credulity or at me, for landing her in it. ‘Of course. I should have realised.’ She pushes at the food on her plate, but she is no longer eating. ‘How silly of me. Isa and her friends used to have this … game,’ she adds to Marc. ‘What was it you called it?’

‘The Lying Game,’ I say. My stomach is twisting, and I see Kate shoot a questioning look from across the table. I shake my head very slightly and she turns back to her neighbour.

‘I should have known,’ Lucy says. She is shaking her head, her expression rueful. ‘You could never believe a word any of them said. What was that one about your father being on the run, Isa, and that was why he never visited? I fell for that one hook, line and sinker. You must have thought me very stupid.’

I try to smile and shake my head, but it feels like a rictus grin, stretched across my cheekbones. And I don’t blame her when she turns away from me, quite deliberately, and begins to talk to the guest on her other side.

Some hour and a half later, and the meal is winding to a close. Across the table from me Kate has been eating grimly and determinedly, as if only by demolishing her meal will she be able to leave. Fatima has picked, and more than once I see her shake her head irritatedly at yet another waiter trying to serve her wine.

Thea has sent away plate after plate untouched, but she’s made up for it with drink.

At last, though, it’s the final speeches, and I feel a rush of relief as I realise this is it – the final furlong. We drink bad coffee, while we listen to a woman I vaguely remember from two or three years above us, called Mary Hardwick. She, it seems, has written a novel, and this apparently qualifies her to make a long, digressive speech about the narrative of the human life, during which I see Kate rise from her seat. As she passes mine she whispers, ‘I’m going to the cloakroom to get our bags and shoes before the rush starts.’

I nod, and she slips around the edges of the tables, taking the route Thea and I used at the beginning of the evening. She has almost reached the main doors when there is a burst of clapping and I realise the speech is over, everyone is standing up, gathering belongings.

‘Goodbye,’ Marc Hopgood says, as he slings his jacket back on and hands his wife her handbag. ‘Nice meeting you.’

‘Nice meeting you too,’ I say, ‘Goodbye, Lucy.’ But Lucy Hopgood is already walking off, looking away from me determinedly, as if she’s seen something very important on the other side of the room.

Marc gives a little shrug and a wave, and then follows. When they are gone I feel in my pocket for my phone, checking for messages, although I didn’t feel it buzz.

I’m still staring down at the screen, when I feel a tap on my shoulder and I see Jess Hamilton standing behind me, her face flushed with wine and the heat of the room.

‘Off so soon?’ she asks, and when I nod she says, ‘Come for a nightcap in the village. We’re staying at a B&B on the seafront and I think a few old girls are planning to meet up in the Salten Arms for a quick one before bed.’

‘No, thanks,’ I say awkwardly. ‘It’s kind of you, but we’re walking back across the marsh to Kate’s, the pub would be miles out of our way. And plus, you know, I left Freya there with a sitter, so I don’t want to be too late.’

I don’t say what I am really thinking, which is that I would rather chew off my own foot than spend another minute with these cheerful, laughing women, who have such happy memories of their schooldays, and will want to talk and endlessly reminisce about times that are much less happy for Kate, Thea, Fatima and me.

‘Shame,’ Jess says lightly. ‘But listen, don’t let it be another fifteen years before you come to one of these things, OK? They run a dinner most years, admittedly not as big as this one. But I should think the twentieth will be something pretty special.’

‘Of course,’ I say meaninglessly, and I make a move to go, but as I do, she catches my shoulder. When I turn, her eyes are bright, and she is swaying, ever so slightly, and I see that she is very, very drunk. Much drunker than I had realised.

‘Oh, sod it,’ she says, ‘I can’t let you go without asking. We’ve been speculating all night on our table and I have to ask this. I hope it’s not – well, I mean, don’t take this the wrong way, but when you all left, the four of you – was it for the reason everyone said?’

The bottom seems to drop out of my stomach, and I feel hollow, as if the food and drink I have consumed tonight have been nothing but sea mist.

‘I don’t know,’ I say trying to keep my voice light and even. ‘What reason did everyone give?’

‘Oh, you must have heard the rumours,’ Jess says. She lowers her voice, glances behind her, and I realise, she is looking for Kate, making sure she’s not in earshot. ‘That … you know … Ambrose …’

She trails off meaningfully and I swallow against a hard, painful lump that suddenly constricts my throat. I should turn away, pretend to see Fatima or someone calling me, but I can’t, I don’t want to. I want to make her say it, this vile thing she’s circling around, prodding at, poking.

‘What about him?’ I say, and I even manage a smile. ‘I haven’t a clue what you mean.’

That’s a lie.

‘Oh God,’ Jess says with a groan, and I don’t know whether her sudden compunction is real or feigned – I can’t tell any more, I’ve spent so long steeped in deceit. ‘Isa, I didn’t … You really don’t know?’

‘Say it,’ I say, and there’s no smile in my voice now. ‘Say it.’

‘Shit.’ Jess looks unhappy now, the alcohol wearing off in the face of my fierce disgust. ‘Isa, I’m sorry, I didn’t mean to stir up –’

‘You’ve been speculating about it all night, apparently. So at least have the guts to say it to our faces. What’s the rumour?’

‘That Ambrose …’ Jess gulps; she looks over my shoulder, looking for a way out, but the hall is emptying fast, none of her friends are in sight. ‘That Ambrose … that he … he did … drawings, of you all. The four of you.’

‘Oh, but not just drawings, right?’ My voice is very cold. ‘Right, Jess? What sort of drawings, exactly?’

‘N-naked drawings,’ she says, almost whispering now.

‘And?’

‘And … the school found out … and that’s why Ambrose … he …’

‘He what?’

She is silent, and I grab her wrist, watching her wince as she feels the pressure of my grip on the fine bones.

‘He what?’ I say, loudly this time, and my voice echoes round the almost empty hall, so that the heads of the few girls and staff remaining turn to look at us.

‘That’s why he committed suicide,’ Jess whispers. ‘I’m sorry. I shouldn’t have brought it up.’ And she pulls her wrist out of mine, and, hitching her handbag up her shoulder she half walks, half stumbles across the emptying hall to the exit, leaving me gasping, holding myself as if against an imaginary blow, trying not to cry.

WHEN AT LAST I pull myself together enough to face the thronged hallway, I force my way into the crowd, looking, desperately, for Fatima, Kate and Thea.

I scan the hallway, the queue for the cloakroom, the toilets – but they aren’t there. Surely they haven’t left already?

My heart is thumping, and my cheeks are flushed from the encounter with Jess. Where are they?

I’m shoving my way to the exit, elbowing aside laughing little knots of old girls and their husbands and partners, when I feel a hand on my arm and turn, relief written all over my face, only to find Miss Weatherby standing there.

My stomach tightens, thinking of our last meeting, the furious disappointment on her face.

‘Isa,’ she says. ‘Always rushing everywhere, I remember that so well. I always said you should have played hockey, put all that nervous energy to good use!’

‘I’m sorry,’ I say, trying to not gasp, trying not to pull away too obviously. ‘I – I have to get back, the babysitter …’