Mary Lee was living in an old farmhouse rented from a local real estate agent. It was on the outskirts of the town, and this was the first time it had been rented outside of the holiday season. The retired dairy farmer had been more than happy to have the extra income. Rented in the name of John Lee, the farmer had been told it was a father and daughter from Sweden. They’d paid up front and caused no trouble.

It was an unremarkable but well-kept two-story building with a few outbuildings that once upon a time had held livestock. Originally there had been land—thirty acres or more—but that had been sold long ago to the developers. What was left was an unkempt border of trees and shrubs that provided the house with some privacy from both the road and the new arrivals in the nearby housing development.

It also gave Lucy Cavendish plenty of places to hide.

Since she had climbed over the fence from one of the new houses, leaving her bike behind someone’s shed, Lucy had been sitting with her back to a large beech tree. It had taken a full five minutes for her heart to stop thumping and her nose to stop hurting. Finally she got up and peered at the rear of the house. She had been watching it for ages; she decided that Mary must have gone to school and that her father was away. Lucy needed to move now. She wasn’t sure how long the house would remain empty—and she was freezing.

Lucy had spent Sunday wondering about the conversation with Itch and Jack in the ambulance. She had come to the conclusion that Itch had been telling the truth when he said they had had nothing to do with the attack. Furthermore, she was sure her attacker was female and very slight—and that description didn’t match any of Itch’s bodyguards.

But then who was the mystery cyclist? Lucy had run through everyone at school who might have seen what she’d done to Jack, and one image kept recurring: the lone figure of Mary Lee standing behind the goal. The goal that Jack had been attacking when Lucy stomped on her hand.

Of course. It had to be Mary.

She was new to the academy, and no one knew that much about her. But she had been so friendly to Itch at Mr. Hampton’s science club—chatting and laughing about this element thing they seemed to have in common.

She looked athletic. She was small.

And she had witnessed what Lucy had done to Jack.

Lucy had no desire to confront Mary. If she was right, the throbbing in her nose and cheekbones was all the reminder she needed of Mary’s strength and brutality. But the more she thought about it, the more certain she was that there was a mystery surrounding this new twelfth grader. She had been accepted, of course; no one had been curious about a new student, even one who said she had just arrived from Sweden. Lucy had messaged some friends from the senior class; none had been to Mary’s house or seen her father. She didn’t appear to be on Facebook, and Google found no record of a John Lee working in pharmaceuticals. Hardly proof of anything, Lucy realized; but when her mother left for work, thinking her daughter would spend the day in bed, continuing to recover, Lucy knew she wanted to investigate further.

Now that she was outside Mary’s house, however, she realized she had no idea what she was going to do next.

Jack’s suggestion that Fairnie should fix up a meeting for Itch and Mary to talk element hunting had been much discussed back at the Lofte house. Nicholas and Jude were happy, the agents were happy, and Chloe had plenty of material to tease her brother with.

“So today will be your first-ever date, won’t it?” she had said that morning before school. “I mean, I don’t think you’ve ever—” She had popped her head around Itch’s door, and a ballpoint pen cap hit her on the ear.

“Oh, ha-ha, Chloe, you’re so funny. I’ve told you—her dad’s got an element collection. It’s here, in town. There’s no Cake to find me new stuff now.”

“OK.” Chloe smiled. “I believe you.”

“And she’s a senior, dummy.” Itch was finding a uniform and hiding his red cheeks. “She’s bound to have boyfriends back in Sweden, anyway,” he said.

“Or a husband—as she’s so old!”

“If it makes it funnier for you, yes, maybe a husband. Happy now?”

Chloe called, “Nice new deodorant, by the way!” as she left his room. The rest of the ballpoint pen followed swiftly afterward.

Fairnie had agreed that Mary could bring her elements to school on Monday. She had the use of her father’s car, and it seemed the safest way to transport a delicate collection.

At break, Itch and Jack had passed Mary in the corridor. “See you in Mr. Hampton’s labs later!” she told them.

“Where’s all the stuff?” asked Itch.

“Going home to get it at lunchtime,” she called over her shoulder.

Jack had giggled as they walked on to their computer science class. “You’re as bad as Chloe,” Itch muttered.

Lucy stood in the damp, cold autumn air outside Mary’s back door. With her heart thundering like a train against her ribs, she tried the handle. Locked. She looked around; the windows were all shut, apart from one she hadn’t noticed earlier—on the second floor above a small conservatory. It wasn’t open by much, but it gave Lucy an idea. The conservatory had once been painted white but had weathered back to the wood. Some of the glass looked loose and there was some uninviting jagged brass decoration on the top, but it was the only way up.

As Lucy found a foothold on the first window ledge, she was glad she had opted for her combat boots and jeans. Reaching for the gutter, she tested its strength, pulling hard. It was heavy and made of iron, but rust had sapped all its strength. A length of it snapped off and came away; Lucy fell with it to the ground. Pain shot through her whole face and she cried out. Once her eyes had stopped watering, her first instinct was to run, but she fought against it and, leaving the gutter where it lay, tried again on the other side of the conservatory. This time the gutter held, and she was able to haul herself onto the roof.

Lying flat and straddling the ornamental brass frill, she found the open window right above her head. She pushed up the metal catch and, reaching for the sill, pulled herself up and through, sliding on her stomach over the ledge.

Itch, Jack, and Chloe sat having lunch together.

“Thought you’d be in the labs,” said Jack. “Wasn’t that the plan?”

Itch nodded. “Fairnie thought the best thing would be for Mary to go home and pick up the elements in her car. She left a few minutes ago. She won’t be long, so I have to hurry.” He shoveled great forkfuls of pasta into his mouth.

“Itch, you’re revolting,” said Chloe as she watched his food disappear. “She won’t like you if you’re burping and farting all afternoon.”

Jack laughed but Itch wasn’t impressed. “For the last time, Chloe, I don’t care if she doesn’t like me! It’s the elements her dad has that I want to see.” He sprayed some pasta over his sister and cousin as he spoke, and apologized. “Look. It’ll be ten minutes—”

Jack held up her hand. “Itch, calm down. We’re only joking. Forget it. Hope she brings in some cool stuff, not just boring old tin.”

“Tin isn’t boring. As you well know!” Itch was going to explain further, but Jack’s hand was up again.

“I know. I’m joking!”

Itch smiled weakly and nodded. “OK—see you after lunch,” he said, clearing his plate.

“Don’t forget, it’s the Oscars first period this afternoon!” called Chloe as her brother scraped his tray into the trash and stacked it with the others. He waved in acknowledgment and headed for the labs.

The “Oscars” was a new idea of Cornwall Academy principal Dr. Dart. The embarrassment of losing the head of the science department after he attacked Itch and his fellow teachers had been followed by some terrible publicity. Local TV and radio—as well as some of the national papers—had covered the story in what Dr. Dart thought was an unnecessarily lurid way. There had been public meetings questioning her competence—along with that of the teachers and the school board. The PTA had had some heated meetings.

So the Oscars were intended to bring some pride back to the school. The “Academy’s Awards,” as they were officially called, were handed out monthly for any special work that had been brought to the principal’s attention. Given that the winners received a certificate and—more important—gift cards, they had become quite a sensation.

“You got any work in for an award, Jack?” asked Chloe.

“Not sure. Littlewood liked my last history essay, but who knows? You? Are you allowed to win two in a row?”

Chloe shrugged; she had won an Oscar for a math assignment on angles. “Dunno. Think they’re making this up as they go along.”

Jack nodded. “I don’t suppose Itch will win anything. But then, he won’t be concentrating much on anything this afternoon!”

Lucy had landed in a bedroom. Crouched under the windowsill, she allowed her aching body to be warmed by the room’s heat. It smelled of showers, shampoo, and wet towels. She was next to a large made-up bed; with a pile of books, newspapers, and magazines under a bedside table. They were in a precarious pile and Lucy glanced at them, afraid to touch or rearrange anything. Instead of the celebrity magazines she expected, she found old copies of The Times, a magazine called Newswatch and a few National Geographics. The smell of the room said it was Mary’s, but no girl Lucy knew only had this sort of reading material. The books on her shelves looked just as boring. Maybe her father was here, after all.

She stood up slowly and walked around the room. No clothes on the floor, all drawers closed. Did anyone of her generation really live like this? Realizing her boots were leaving marks in the carpet, Lucy leaned on the dresser to remove them. She placed them under the window and walked around the bed into the bathroom. She smiled—there was no doubt this was a girl’s domain. Makeup, deodorant, and perfumes lined the windowsill. A razor and more bottles stood in the shower’s soap dish.

Out on the landing there were two other doors leading onto smaller bedrooms. They looked unused: each had a single bed with fresh bedding folded up neatly at one end. There was no trace of Mary’s father. Lucy wondered for the first time if there really was a Mr. Lee.

Moving more quickly now, Lucy padded down the stairs. Both front rooms were shuttered and dark, the light in the hall coming from the frosted window in the front door at one end and the kitchen at the other. Drawn to the warmth coming from the old Aga stove, she walked around the kitchen, looking for … what exactly? All Lucy had was an idea: that there was something not quite right about Mary, and that her house must hold a clue somewhere. But the kitchen felt like an unlikely place for secrets. The fridge and pantry held only a few items, essentials really. The drawers and dresser contained the tired cutlery and crockery used by everyone who had ever rented the house. A pair of straw-colored sandals were propped up against the heat of the stove.

Lucy was just heading for the first of the shuttered front rooms when she heard a car pull up outside.

Mary had returned.

Lucy ran back into the kitchen, her heart pumping and her eyes wide. By the back door she found a small utility room and an open door to an office she hadn’t seen before. There was the sound of a car door slamming, swiftly followed by a key in the lock. Lucy dived into the darkness of the utility room and slid behind a drying rack with jeans, T-shirts, and underwear draped over it. She sat on the cold tiled floor with her back against a bucket and mop and started to shake. As her eyes grew accustomed to the dark, the clothing she was hiding behind came more into focus and a flash of fluorescent green caught her eye. Her stomach lurched and another shot of adrenaline flooded her body. She recognized the bright logo of a famous cycling sportswear manufacturer. She touched the black fabric. Lycra.

The woman on the bike. It had been Mary. Instinctively, Lucy covered her damaged face with both hands.

She hadn’t had time to shut the utility door properly—she was likely visible from the kitchen. She listened to Mary’s movements, praying that what she wanted was in one of the front rooms. It sounded as if she was carrying something out of the house—presumably to the car; Lucy waited to hear the door slam before she moved. Then she jumped as a shrill, warbling ringtone came from the office. Lucy recognized the sound: it was an incoming Skype call.

Mary came running back into the house. She flew past the utility room and into the office; immediately she started shouting at the screen. Through the door Lucy could hear a disembodied female voice arguing with her. She was sure it was an argument even though it wasn’t in English; in fact she didn’t recognize a single word. Mary kept repeating, “Leila”—the other person’s name maybe—and the other voice, “Shivvi.” Was that Mary’s nickname?

The conversation finished with “Leila” saying, “Selamat jalan,” and Mary repeating, “Selamat jalan.”

Lucy caught a glimpse of Mary as she passed the door, and seconds later heard the front door close and the car pull away. Still not wanting to move, she stayed on the floor and reached for her phone. She typed in different spellings of the words she had just heard, and after two attempts she was close enough for Google to suggest, Do you mean selamat jalan? She clicked on the first suggestion:

“Selamat jalan—Malay interjection meaning bon voyage/good-bye.”

Lucy switched off her phone and went into the office. On the computer screen the Skype log said the call was from LEILA S, and the image was of a smiling black-haired woman in her twenties. For a mad moment Lucy was tempted to call back. She hovered by the computer, then sat down.

Wow, Mary’s Malaysian, she thought and, her hands trembling again, clicked on the MAIL icon. Long lists of emails appeared, and she scanned the first few. They were mostly in a foreign language—Malay presumably—but they were all addressed to “Shivvi.”

She searched for correspondence from “Leila S,” and there were three emails. As she scanned the incomprehensible text, three words jumped out at her. In the second paragraph there was a reference to Greencorps, whom she knew were the sponsors of the Cornwall Academy. This was followed by Nathaniel Flowerdew, and Lucy shivered. What did Mary—or Shivvi—have to do with the disgraced head of the science department? Risking a few more seconds at the computer, she Googled Shivvi + Greencorps + Flowerdew.

Two minutes later, her head spinning, she clicked CLEAR HISTORY, and stared at the screen. The computer’s screensaver appeared, and Lucy leaned closer: six wet-suited divers squinted and smiled out at her. They appeared to be standing on the deck of an oil rig, and behind them, her arms spread wide and beaming proudly, was Mary Lee.