The girl didn't look before crossing the road.

That was what the driver said later. She didn't look left or right. She'd seen a friend on the opposite pavement, and she simply walked across to join him, not noticing that the lights had turned green, forgetting that this was always a busy intersection and that this was four o'clock in the afternoon when people were trying to get their work finished, hurrying on their way home. The girl just set off without thinking. She didn't so much as glimpse the white van heading toward her at fifty miles an hour.

But that was typical of Scarlett Adams. She always was a bit of a dreamer, the sort of person who'd act first and then think about what she'd done only when it was far too late. The field hockey ball that she had tried to thwack over the school roof, but which had instead gone straight through the headmistress's window. The groundsman she had pushed, fully clothed, into the swimming pool. It might have been a good idea to check first that he could swim. The sixty-foot-tall tree she'd climbed up, only to realize that there was no possible way back down.

Fortunately, her school made allowances. It helped that Scarlett was generally popular, was liked by most of the teachers, and, even if she was never top of the class, managed to be never too near the bottom. Where she really excelled was at sports. She was captain of the field hockey team (despite the occasional misfires), a strong tennis player, and an all-around winner when it came to track and field. No school will give too much trouble to someone who brings home the trophies, and Scarlett was responsible for a whole clutch of them.

The school was called St. Genevieve's, and from the outside it could have been a stately home or perhaps a private hospital for the very rich. It stood on its own grounds, set back from the road, with ivy growing up the walls, sash windows, and a bell tower perched on top of the roof. The uniform, it was generally agreed, was the most hideous in England: a mauve dress, a yellow jersey, and, in summer months, a straw hat. Everyone hated the straw hats. In fact it was a tradition for every girl to set the wretched thing on fire on their last day.

St. Genevieve's was a private school, one of many that were clustered together in the center of Dulwich, in South London. It was a strange part of the world, and everyone who lived there knew it. To the west there was Streatham and to the east Sydenham, both areas with high-rise apartment buildings, drugs, and knife crimes. But in Dulwich, everything was green. There were old-fashioned tea shops, the sort that spelled themselves shoppes, and flower baskets hanging off the lampposts. Most of the cars seemed to be SUVs, and the mothers who drove them were all on first-name terms. Dulwich College, Dulwich Prepatory School, Alleyn's, St. Genevieve's . . . they were only a stone's throw away from each other, but of course nobody threw stones at each other. Not in this part of town.

It was obvious from her appearance that Scarlett hadn't been born in England. Her parents might be Mr. and Mrs. Typical Dulwich — her mother tall, blond, and elegant, her father looking like the lawyer he always had been, with graying hair, a round face, and glasses — but she looked nothing like them. Scarlett had long black hair, strange hazel-green eyes, and the soft brown skin of a girl born in China, Hong Kong, or some other part of Central Asia. She was slim and small, with a dazzling smile that had gotten her out of trouble on many occasions. She wasn't their biological daughter. Everyone knew that. She had known it herself from the earliest age.

She had been adopted. Paul and Vanessa Adams were unable to have children of their own, and they had found her in an orphanage in Jakarta. Nobody knew how she had gotten there. The identity of her birth mother was a mystery. Scarlett tried not to think about her past, where she had come from, but she often wondered what would have happened if the couple who had come all the way from London had chosen the baby in cot seven or nine rather than the one in cot eight. Might she have ended up planting rice somewhere in Indonesia or sewing Nike sneakers in some city sweatshop? It was enough to make her shudder . . . the thought alone.