The flat in Notting Hill is the kind of place that looks charming in photographs and requires a certain amount of goodwill in person. One bedroom, top floor, which sounds more glamorous than it is given that the floor below practises what I can only assume is competitive furniture rearranging at midnight and the boiler on the landing makes its feelings known at three in the morning. The living room is mostly books and the kitchen is mostly Marcus's editorial notes, stuck to the fridge with magnets I have accumulated from every destination I have ever visited and cannot bring myself to throw away. There is a print of the Alhambra above the sofa that Leo chose and I kept because I refuse to let him have Granada as well as everything else.

It is mine. After fourteen months of lawyers and paperwork and the specific misery of dividing a life into two piles, that still matters more than I expected it to.

I am sitting on the floor of it now, at half past seven on a Tuesday evening in September, surrounded by the evidence of my own incompetence. One open suitcase. One container of pad Thai going cold beside my left knee. One notebook already half-full of research I did instead of sleeping. The copy of Mediterranean Light by cultural critic and travel writer Sebastian Vane that has been on my bedside table for three weeks, forty percent read, with a Waterstones receipt still inside it because I bought it the week Marcus gave me this assignment and have not yet decided what I think about that.

I am going back to Santorini.

Marcus gave me the assignment three weeks ago, sliding it across his desk with elaborate casualness, mispronouncing Imerovigli so badly I had to correct him twice, and telling me to file six thousand words by the following Friday. I am grateful and furious about this in equal measure, which is more or less my permanent state with him.

My phone rang from somewhere under a pile of linen trousers. I extracted it with one hand without dropping the Pad Thai I had been expecting Delia, or possibly Gerald checking in on behalf of my mother, who has started briefing him as a forward operating presence whenever I'm about to do something she considers inadvisable.

"You've packed the wrong shoes again," said Delia, without saying hello. This is her primary mode of greeting when I'm about to go somewhere. She has been doing it since I was twenty-three and it has been correct approximately eighty percent of the time.

"I haven't even told you what shoes I've packed."

"Pippa. You own three pairs of sandals. One of them has a broken strap you've been meaning to fix since May. One of them you only bought because they were in a sale and they give you blisters. And one of them is perfectly fine but you always forget to pack that one."

I looked down at the suitcase. I had packed the sale sandals.

"The broken strap one is fine," I said. "I've safety-pinned it."

There was a silence of the specific quality that only younger sisters can produce.

"How are you actually feeling about it?" Delia said, in her other voice. The one that means she has put down whatever she was doing and is actually asking.

I ate some Pad Thai and considered lying. Delia has an alarming ability to detect a lie even through poor phone signal, which she inherited from our mother and which I have never once successfully circumvented in thirty-four years of trying.

"Fine," I said. "Honestly. It's been two years. It's a work trip. It's Santorini, not a crime scene."

"It's where you went on your honeymoon."

"It's where approximately forty thousand other couples also go on their honeymoon. It's a very popular island, Delia. I'm not going to turn a corner and find Leo there."

"He did call last week."

"He calls occasionally. It doesn't mean anything."

"Pippa."

"I'm fine. I'm going to write a beautiful piece about a clifftop villa, eat my body weight in fresh seafood, and come home with a tan and six thousand words. That is the entire plan."

Another silence. Shorter this time.

"Ring me when you land," she said. "And pack the other sandals."

✦ ✦ ✦

I did not pack the other sandals. I did ring her when I landed.

The thing about arriving at Santorini is that the island ambushes you from the air. You come in low over the caldera — that vast, drowned crater of the ancient volcano that remade this place entirely — and suddenly there it is below you: a crescent of cliff face rising sheer from the water, its top edge lined with white. From up here the buildings look like something a child has pressed into the rock face, small and bright and improbable, tumbling down toward a sea that is doing something with colour that should not be physically possible. Not blue. Something more than blue. A shade that exists, as far as I can tell, only here and only in the specific light of the Aegean in September, when the season is turning and the sky has deepened from the bleached white of August into something richer and more honest.

I pressed my forehead against the plane window like an idiot and wrote three sentences in my notebook and crossed them all out. Too much. I always do too much with Santorini.

My father would have understood. He talked about this island the way he talked about all the places he loved — specifically, warmly, with the particular attention of someone who has actually looked at a thing rather than merely seen it. He took a trip alone every year, which suited everyone: he wanted to wander and look at things at his own pace, Siobhan preferred somewhere slower, and Delia and I were at an age when the idea of following our father around historical sites held approximately no appeal. We had our own family holidays. But these trips were his, and he came back from them full of stories. He had come here years before I did and described it in enough detail over a Sunday dinner that I had felt I'd already been when I finally arrived. The caldera. The path along the clifftop. The little boat across to Thirassia and the tiny chapel someone had told him about — a tiny exokklisi, he'd said, using the Greek word carefully, pleased with himself. He had loved it.

I was twenty-two and more interested in the bread at the time. I wish I had listened better. I always wish that now.

The airport at Santorini is small and warm and immediately, cheerfully chaotic. In September it still has the energy of high season — the queues, the overladen trolleys, the tour groups clustering around guides holding up numbered signs — but there is something slightly looser about it than August, a first exhale. I collected my bag, straightened the linen shirt I had put on in London at six in the morning and which had already made certain decisions about the rest of the day, and walked out into the September heat.

It hit me like a gift. Warm and dry and faintly herby, the scrubby vegetation of the island baking gently in the afternoon sun. After a grey London September it felt almost indecent. I stood in the car park for a moment with my eyes closed and my face tipped up and thought: there it is. That thing that keeps making me come back.

Eleni Papadakis was waiting for me just beyond the arrivals door, holding a piece of paper with RAFFERTY written on it in enormous letters, as though I might miss her. Richard had arranged for her to collect me, he'd said in his email. She was small and upright and seventy-four, with sharp dark eyes and the expression of someone who had seen everything this island had to offer and found most of it wanting. She looked at me, looked at my suitcase, looked at my shoes, and said something in Greek that I didn't catch but that felt pointed.

"Yiayia Eleni?" I said, because Richard had told me she preferred it. Also because she had the immediate, non-negotiable energy of someone's grandmother. Not necessarily mine. But she had decided today it was going to be mine.

Her expression shifted into something warmer. She pressed something small into my hand. A tiny blue glass eye on a thin cord, the kind you see hanging in every shop and doorway on the island. An evil eye charm.

"For protection," she said firmly, in English.