As a place to spend the summer, Port Sentinel probably had its good points, but it was doing a good job of hiding them. I trudged down Fore Street, the main and only street in town, feeling the rain soak into my jeans. It had been pouring since the night before, when my mother and I arrived in the middle of a thunderstorm and unloaded all our belongings in a serious cloudburst, running from the car to the holiday cottage in total hysterics. It would take weeks for everything to dry out completely.

When I woke the following morning to steady drizzle the weather pretty much matched my mood. The sky was an ominous shade of gray that suggested there was plenty more rain to come. There was no TV in our rented cottage, or access to the internet, and I had lasted through four chapters of the witless romantic novel I'd found on a shelf before I gave up. Just because the hero was a ruggedly handsome cowboy, I didn't see why it gave him the right to be so rude all the time. Plus the heroine was a twit. I couldn't even be bothered to flick to the end to make sure they really did live happily ever after. I grabbed my jacket (rainproof, hooded, essential accessory for a summer holiday in England) and went to find Mum.

She was in her bedroom, I discovered, lying on the bed, staring at the ceiling.

"Are you OK?"

"Fine. This is called relaxing. I'm relaxing."

"You sound as if you're trying to convince yourself."

She grabbed a pillow and threw it at me. "Leave me alone."

"What? I'm just saying, you don't look relaxed."

"I'm trying. This is a holiday, after all."

A holiday she had decided we were going to take. Molly Tennant, née Cole, returning to her roots accompanied by her teenage daughter, Jess, after an absence of many years and a bitter divorce. Because there was absolutely no chance of that being awkward. I didn't bother with I-told-you-so. "I'm going out for a wander. Do you want to come?"

She shook her head.

"You're going to have to leave the house sometime."

"Not yet, though."

"Mum ..."

"I'm building up to it."

"I'll leave you to it, then. I'll be back soon."

Which was no word of a lie, because it wasn't as if it was going to take a long time to look around. Port Sentinel wasn't a one-horse town, but that was only because they'd upgraded the horse to a Range Rover for the sake of the out-of-towners who owned holiday homes there. The locals probably had to share a three-legged donkey, but they were very much less important than the bankers and brokers who'd built large houses all the way across the hill above the town. They were all at least five times the size of the tiny fishermen's cottages and pastel-painted terraced houses that had once been the only buildings in Port Sentinel, before it became fashionable. Huge picture windows stared out blankly at the view, reflecting nothing but gray skies and the gravel-colored sea. It would be pretty if the sun ever came out, I admitted grudgingly. Very grudgingly after I had stepped off the pavement into a puddle and soaked my right foot. Very grudgingly indeed after a blonde in a four-wheel drive had come within inches of mowing me down as she sped down the road, huge sunglasses firmly in place despite the weather.

Fore Street was small and narrow, the old buildings leaning against one another drunkenly when you looked above the shopfronts. Half the shops were little boutiques and designer outlets too exclusive for me to consider visiting, even to get out of the rain. The other half consisted of a fairly random collection of teashops, charity shops, junk shops, and we-sell-everything mini-markets wreathed in brightly colored displays of plastic beach toys. They took up most of the narrow pavement. Passing one, I pushed an inflatable whale out of my way and collided with a girl who had been hidden behind it, heading in the opposite direction.

"Sorry." I wasn't, in fact; it was at least as much her fault as mine. But instead of apologizing in return as I had expected, the girl stared at me for a long moment from under her dripping umbrella. I had plenty of time to notice very perfect mascara standing out like stars around her wide eyes, and the serious diamond studs in her ears, and the expensively highlighted hair, and the white skinny jeans, and the sky-high wedges, and the pale-pink polo shirt she was wearing with the collar flipped up, and the Burberry mini-trench that had cost more than my entire wardrobe put together. She looked far more rattled than a near-miss should have made her — stunned, in fact. Alarmed. Panicked. And as a cascade of raindrops fell between us, I realized the hand that held the umbrella was shaking. Rainy it might have been, but it wasn't cold. Not even a little bit.

She stepped sideways eventually, still staring, and I walked on, wondering if she had just never seen anyone in frayed jeans and battered trainers on Fore Street before. I wasn't wearing makeup, either. Call the fashion police, quick.

I probably wouldn't have thought much more about it if it hadn't been for two things. One was the old lady who opened a shop door right in front of me a minute later so I caught sight of the street behind me reflected in the glass — including a perfect view of the girl standing under her umbrella, still gazing in my direction, now on her mobile phone, talking urgently. The other was the fact that three other people stopped to gawp at me in the space of the next three minutes: two girls on the other side of the road who nudged each other as soon as they spotted me, and a middle-aged woman who peered at me short-sightedly and started to wave, then dropped her hand and hurried on. I knew I was blushing, which was annoying in itself. If this was what it was like to be a celebrity I'd be quite happy to remain obscure forever.

But I was never going to be obscure in a small town like Port Sentinel. It was one of the many reasons why I hadn't been thrilled to hear we were spending the summer there. I had waited to tackle Mum until we were actually in the car, halfway down the motorway, London not even a brown smudge in the rear-view mirror any more. I'd read in a parenting book Mum had borrowed from the library that the car was the ideal place for awkward conversations with teenagers; I didn't see why that shouldn't work just as well the other way round. (If you're wondering why I was reading a parenting book, all I'll say is: knowledge is power. I like to spot the psychological trickery well in advance. And if you're wondering why Mum was reading a parenting book, so was I.)

"The thing I don't understand," I had said carefully, "is why now."

"Sorry?" My mother, who is neither deaf nor stupid, played for time.

"Why now? You haven't gone near Port Sentinel or your family since before I was born, and suddenly we're spending the summer there. Which, by the way, you didn't even discuss with me."

"There was nothing to discuss, Jess." She kept her eyes on the motorway and her knuckles were white as she gripped the steering wheel. That didn't mean anything; she was a nervous driver at the best of times. But I knew I was making her tense.

Which was no reason to stop.

"I was sort of looking forward to spending the summer in London. You know, with my friends. And with Dad," I added.

"I seem to recall someone complaining about their friends being away. Isn't Lauren in France?"

"Staying with a family in Provence. Her mum is completely obsessed with her...