Kate takes a deep breath and for a minute I think she’s going to persist, but then she turns and stalks off ahead of us up the path.

‘Fine.’ It’s muttered under her breath, so low that I’m not sure if I heard.

‘That was weird,’ I whisper to Fatima, who nods.

‘I know. What’s going on? But I wasn’t being unreasonable, was I? I mean –’ She gestures to the flowing, fragile silk, the easily caught jewels. ‘Seriously, right? There’s no way I could have got through those thorn bushes.’

‘Of course not,’ I say as we increase our pace to catch up with Kate’s retreating back. ‘I don’t know what she was thinking.’

But I do know. As soon as we get to the place where we always used to turn, I know instantly, and I can’t believe I had forgotten. And I understand, too, why Kate took Thea north up the Reach for their walk this afternoon, instead of south towards the sea.

For where our route turns right, over a stile onto the marsh, the shore path carries on towards the sea, and in the distance, almost hidden in the lee of a sand dune, I can see a white shape, and the blue-and-white flutter of police tape.

It is a tent. The sort used to shelter a site where forensic samples are being taken.

My heart sinks, a sickness fluttering in my stomach. How could we have been so crass?

Thea and Fatima realise it too, at the same instant. I can see by the way their faces change, and we exchange a single, stricken look behind Kate’s back as she walks ahead of us to the stile, her face averted from the stark beauty of the shore, and the sparkling sea stretching far out, as far as the eye can see, and in the midst of it all, that unassuming little tent that has changed everything.

‘I’m sorry,’ I say, as Kate swings her leg over the fence, the rose-patterned silk fluttering in the wind. ‘Kate, we didn’t think –’

‘It’s fine,’ she says again, but her voice is stiff and hard, and it is not fine. How could we have forgotten? It’s not like we didn’t know. It’s why we’re here, after all.

‘Kate …’ Fatima says pleadingly, but Kate is over the stile, and striding onwards, her face turned away from us so we cannot see her expression, and we can only look at each other, wretched, guilty, and then hurry to catch up.

‘Kate, I’m sorry,’ I say again, catching at her arm, but she pulls out of my grip.

‘Forget about it,’ she says, and it’s a punch in the gut, an accus-ation I can’t refute. Because I already did.

‘Stop,’ Thea says, and there’s a note of command in her voice, a sound that I haven’t heard for years. She used to use it so easily, that whip-crack tone that more or less compelled you to listen, even if you didn’t obey. Stop. Drink this. Give me that. Come here.

Somewhere along the line she stopped – stopped ordering others around, became frightened of her own authority. But it’s back, just for a flicker, and Kate turns, halting on the short, sheep-cropped turf with a look of resignation in her eyes.

‘What?’

‘Kate, look …’ The note is gone now, Thea’s voice is concili-atory, uncertain, reflecting all our feelings as we stand around, unsure what to say, unsure how to make the unbearable OK when we know we can’t. ‘Kate, we didn’t –’

‘We’re sorry,’ Fatima says. ‘We really are, we should have realised. But don’t be like this – we’re here for you, you know that, right?’

‘And I should be more grateful?’ Kate’s face twists, and she tries to smile. ‘I know, I –’

But Fatima interrupts.

‘No. That’s not what I’m saying – for fuck’s sake, Kate, when did gratitude ever come between any of us?’ She spits out the word like a swear word. ‘Gratitude? Don’t insult me. We’re beyond that, aren’t we? We certainly used to be. All I meant was, you think you’re alone, you think you’re the only one who cares, you’re not. And you should take this – all of us –’ she waves a hand round at our little group, our long black shadows streaming across the marsh in the evening sun – ‘as proof of that. We love you, Kate. Look at us – Isa trekking down with her baby, Thea throwing in work at a moment’s notice, me dropping Ali, Nadia, Sam, all of them, for you. That’s how much you mean to me, to us. That’s how much we will never let you down. Do you understand?’

Kate shuts her eyes, and for a minute I think she may be about to cry, or rail at us, but she doesn’t, she reaches out, blind, for our hands, and pulls us towards her, her strong, paint-covered fingers hard against my wrist, as if we’re keeping her afloat.

‘You –’ she says, and her voice cracks, and then our arms are around each other, all four of us, huddled together like four trees twisted in the coast winds into a single living thing, arms tangled, foreheads pressed, warmth against warmth, and I can feel them, the others, their pasts so woven with mine that there’s no way to separate us, any of us.

‘I love you,’ Kate croaks, and I am saying it back, or I think I am, the chorus of choked voices must include mine, but I can’t tell, I can’t tell where I end and the others begin.

‘We go in together,’ Fatima says firmly. ‘Understand? They broke us once, but they won’t do it again.’

Kate nods, and straightens, wiping her eyes beneath the mascara.

‘Right.’

‘So, we’re agreed? United front?’

‘United front,’ Thea says, a little grimly, and I nod.

‘United we stand,’ I say, and then I wish I hadn’t, because the unspoken final half of the saying hangs in the air, like a silent echo.

DO YOU REMEMBER …

That’s the refrain running through our conversation as we trudge the last mile of the walk across the marshes.

Do you remember the time Thea got caught with vodka in her sports bottle at the away hockey match with Roedean?

Do you remember when Fatima told Miss Rourke that fukkit was Urdu for pen?

Do you remember when we broke out to go night swimming, and Kate got caught in the rip tide and nearly drowned?

Do you remember – do you remember – do you remember …

I thought I remembered everything, but now, as the memories sweep over me like floodwater, I realise that I didn’t, not fully. Not like this – not so vividly that I can smell the seawater, see again Kate’s shaking limbs, white in the moonlight, as we staggered up the beach with her. I remembered, but I didn’t remember the detail, the colours, the feel of the playing-field grass beneath my feet and the sea wind against my face.

But it’s as we cross the last field and climb the last fence that Salten House comes into view and it really hits home. We are back. We are really and truly back. The realisation is unsettling, and I feel my stomach tighten as the others fall silent, knowing that they must be remembering as I am, some of the other memories, the ones we have tried to forget. I remember Mark Wren’s face when a group of fifth years met him on the coast road one day, the tide of red climbing up the back of his neck as the sniggers and whispers started, the way he hung his head and shot a look at Thea that was pure misery. I remember the look of alarm on a first year’s face as she turned away from Fatima and me in the corridor, and I realised that she must have heard rumours about us – about our sharp tongues, and capacity for deceit. And I remember the expression on Miss Weatherby’s face that final day …

I am suddenly glad that Salten House has changed, far more than Salten itself which gives the air of being set in stone and salt. Unlike the Tide Mill which has only grown more battered with the years, there is a perceptible air of smartness to the place now, which is absent from my memories. Whatever impression it tried to give, Salten House was never a top-tier school in my day. It was, as Kate had said, a ‘last-chance saloon’ in many ways – the kind of place that would have space for a pupil enrolled in a hurry due to trouble at home, and would not ask questions about a girl kicked out of three other schools in a row. I remember noticing, when I arrived that first day so long ago, that the paintwork was peeling and salt-stained, the lawns were yellowing after a hot summer. There were weeds growing up through the gravel of the drive, and in among the Bentleys and Daimlers, many parents drove Fiats and Citroëns and battered Volvos.