I think that was the same week she invited me to her house for the first time. Normally, I was collected from school by whichever au pair Angus was employing at the time, or sometimes Mrs. Green. That day, though, Jessica and I walked home from school to her house, right in the middle of the village, next to the post office. For me, shepherded about, overseen and driven everywhere, it felt rather thrilling to be walking along the pavement with my best friend, swinging our bags and chatting. It was a beautiful day; we kept turning our faces to the sun and shutting our eyes, half blinded by light.

I knew most people didn't live in a house as big as Caernaven but even so, the first sight of Jessica’s house momentarily surprised me. It was a tiny cottage, one of the many stone-built terraces that made up the majority of our village housing. The front door was painted a cheerful shade of blue and the door knocker was of the same shiny brass as the button on Jessica's shoe. She had her own key to the door which impressed me.

Jessica's house was empty, humming with silence.

"Mummy's at work," said Jessica, showing me into the tiny kitchen. "She leaves me my tea - look, there it is. She's done yours, too."

There were two plates on the kitchen counter, both covered in clingfilm, heaped with salad and a slice of quiche and some grapes. We each took one and I followed Jessica through to the back garden. It felt rather delightfully like a picnic and I felt envious. I wanted to come home to this tiny cottage and have my dinner in the garden too. After we'd eaten our tea (and that was another thing that I found strange, as tea in our house was always drunk in a cup), Jessica showed me the playhouse that her dad had built, the old robin's nest in the hedge, the fourteen goldfish in a tiny, weed-choked pond.

Finally, we climbed the stairs to her bedroom.

The front door opened as we were halfway up and a tall, grey-haired man walked in. He was thin and slightly crumpled and, for an odd second, I thought he looked as though he were made out of paper.

"Hi, Dad," said Jessica. She bounded down the stairs and kissed him. He seemed to fold in half as he bent down to her.

"Hello, darling. Who's your friend?"

I stood where I was on the stairs, one hand on the banister. I was shy with adults I didn't know.

"This is Maudie, she's from Scotland."

He smiled at me from his withered face. "Hello, dear."

It was fully dark by the time the front door opened again and Mrs. McGaskill appeared.

It's hard for me to remember how I felt about her then, untainted by subsequent events. I know that from very early on, I liked her. Very quickly, I loved her. By the time of our holiday in Cornwall, I almost worshipped her. It was that intensity of feeling that made what happened later so exquisitely painful. Of course, I was looking for a mother-figure and any woman would have done.

She was thirty-two when I met her. In looks she resembled Jessica, tall and slim with messy blonde hair that fell to her shoulders. Both she and Jessica, and myself, were the same 'type'; Scandinavian in colouring, fair-skinned, blonde and blue-eyed; lanky and fine-boned with delicate joints. I was a little frecklier than the both of them and didn't tan so well in the sun, but for all that, my secret pleasure was to imagine they were my mother and sister. I felt a fierce, private joy when strangers mistook us for just that.

Jessica and her mother had a tempestuous relationship. Both were quick anger and they constantly pitted their wills against one another. There were often raised voices, slammed doors, short storms of tears. "You're driving me mad!" I heard Mrs. McGaskill shout one day and Jessica retorted, "I'm not - I'm not even trying." But lying underneath all these histrionics, like a solid slab of bedrock, was a deep love, obvious to all. Perhaps it was because Jessica was an only child.

I wasn't aware of any rift between her mother and father, not really. I was too young. But even then, I could see how dismissive Mrs. McGaskill was of her husband, how easily he seemed to fade into the background when Jessica and her mother were there. When he wasn’t directly before me, I had trouble remembering what he looked like. I had my own father, hard and forbidding as he was; I wasn't looking for another.

It was Angus who suggested Jessica come to our house for a change. For once, he was waiting for me at the school gates when classes finished and a tsunami of children streamed out. I was listening to Jessica tell me a new joke about a gorilla and a hamster and laughing so hard that at first I didn't recognise the tall figure leaning against the bonnet of the car and talking to Mrs. McGaskill.

"What's wrong?"

"It's my dad," I said. Suddenly I was excited and embarrassed at the same time. Jessica caught sight of her mother standing next to Angus and grabbed my hand, dragging me forward as she called to her mother.

"Hello, you two," she said as we ran up, flushed and breathless. "Maudie, I've just been talking to your daddy."

I felt suddenly shy of them both.

"Hello, Maudie," said Angus, holding out his large hand. I took it uncertainly; I wasn’t used to him touching me. "And you must be Jessica."

"That's right," said Jessica, bold as you like. "Is it okay if Maudie comes to my house for tea?"

The two adults exchanged amused glances.

"Well now," said Angus. "We thought you might like to come to our house for tea, for a change. How about that?"

I felt an enormous burst of excitement but I said nothing, watching Jessica's face for a clue to her feelings.

She grinned broadly. "Yes, yes, yes!"

Mrs. McGaskill laughed. "Well, that's easily settled. Jessica, I'll drop some clothes off for you later tonight and you can stay the night. How about that?"

We clambered into the back of the Land Rover. I felt a momentary qualm as Jessica perched on the uncovered metal of the wheel arches; it looked so dirty and uncomfortable in the back, the floor smudged with mud and wisps of straw. But Jessica seemed oblivious to it all, almost bouncing with excitement as we pulled away from the school.

The Land Rover crunched over the gravel of the drive as we neared Caernaven. I looked out of the window. It was odd, but it was almost as though I were seeing with Jessica's eyes. We rolled to a halt and Jessica fell silent, her almost ceaseless chatter falling away in a sigh. I watched her eyes widen as she looked out of the window.

We walked through into the hallway. Jessica seemed diminished by the house: her usual effervescence gone flat and quiet. I took hold of her hand and pulled her after me, running her through the hallway and the dining room and the other corridor and finally into the kitchen, where Mrs. Green was preparing our evening meal.

"Hello, Maudie," she said, her hands busy with a vegetable peeler.

I introduced Jessica to Mrs. Green and asked whether we could have something to eat.

"You'll have to wait for dinner, love. Why don't you take Jessica out and show her the garden?"

I pulled Jessica down the kitchen corridor, past the cellar door and onto the side terrace. Heat shimmered up from the flagstones beneath our feet and the air was sweet with the scent of herbs. I picked a leaf from the lemon balm and held it under Jessica's nose.

"Smell."

"Mmmm," said Jessica, sniffing. Then she drew her head back.

"Was that your gran?" she said.

Something in me recoiled. Mrs. Green, my grandmother?

"No, silly," I said, trying to laugh. "She's the housekeeper."