Charlie Thorne and the Last Equation Read online

  “This will have to be an unsanctioned mission,” Carter said. “Completely off the books. There can’t be any record that the CIA is coercing twelve-year-olds to work for us.”

  Dante smiled. “Of course not.”

  “That means a bare-bones operation as well. Only you and one other agent.”

  Dante’s smile faded. “Only one other? That’s crazy!”

  “Weren’t you just telling me it was time to try something crazy? If it helps, you can select whoever you want.”

  Dante didn’t hesitate for a second. “Milana Moon.”

  Director Carter nodded. Even though she had thousands of agents working under her, she knew exactly who Moon was. The fact that Dante had named her so quickly simply confirmed his intelligence to her. “Fine. If she’ll agree to it.”

  “I think I can convince her.”

  “Then we’re done here.” Carter snapped to her feet and slid the file back across the conference table to Dante. “Destroy that. And then go find Pandora.”

  TWO

  Snowmass Mountain

  Pitkin County, Colorado

  One day later

  No one had skied Deadman’s Drop yet that year.

  To begin with, it was illegal, lying outside the ski area boundary. Second, it was difficult to get to. After you took the Elk Camp lift all the way to the top of the mountain—11,325 feet above sea level—you still had to hike to get there. Up another mountain ridge. Through the snow. Struggling to get a breath in the thin air, lugging your skis or snowboard, until you finally reached the drop-in point.

  But the real reason no one had skied Deadman’s yet was because it lived up to its name and was extremely dangerous. Deadman’s Drop was a couloir, a steep and narrow gouge in the rock, a sixty-degree slope flanked by sheer walls only a few feet apart. There was little room for error—and if you screwed up and busted your leg or tore an ACL, they couldn’t send the ski patrol to get you. You’d have to claw your way out by yourself. And if all that wasn’t scary enough, the couloir ended at a cliff. The ground simply dropped away, leaving a fifty-foot plummet down to the Grey Wolf ski run. There was no way out except over the edge.

  Even if you did make it, and managed to stick the landing without breaking a leg or bashing your head on a rock, there was a decent chance the ski patrol would come after you—as you had now landed back on Snowmass property—and they’d yank your ski pass for the rest of the year as punishment for going outside the boundary. Unless you could outrun them, which was highly unlikely, because the ski patrol was staffed by incredible athletes who skied one hundred days a year.

  But Charlie Thorne was skiing Deadman’s Drop anyhow.

  For her it was pure, unadulterated bliss. Two months’ worth of virgin snow was piled up inside the couloir, and her skis floated over it as she fired through, whooping with joy. She didn’t have the grace of an adult skier yet, slewing about like a rhino on roller skates, but she was a natural athlete with the devil-may-care attitude of a teenager, so she barreled ahead recklessly. Her long dark hair was tucked into a ski helmet, and her green eyes were hidden behind goggles, so all that was visible of her was her broad smile, which her friends considered a near-permanent fixture upon her face.

  It was noon on a Tuesday. Charlie should have been in school.

  Theoretical physics, to be specific.

  But then, Charlie had shown up to her theoretical physics class only once this entire year besides exam days. She had arrived late on the first day of school, listened to fifteen minutes of Dr. Fromer’s lecture, then grown bored and left to go mountain biking. Of course, Dr. Fromer hadn’t been pleased about any of this. So he had thrown a bunch of extra questions into her most recent exam that weren’t on anyone else’s—on subjects that weren’t even covered in the textbook—just to flunk her and teach her a lesson in humility while he was at it.

  Charlie had aced the exam anyhow. She hadn’t even needed the entire testing period. She had just sauntered in and casually done the math, the way other people might have jotted down a thank-you note, while all around her students ten years older than her—students who were majoring in theoretical physics—were tearing their hair out in frustration. It had taken her only thirty minutes, and she didn’t even bother to check her work. And most infuriating of all, she had caught a mistake of Dr. Fromer’s, circled it in red, and written, “Sloppy work. Try harder next time.”

  Similar things had happened in all of Charlie’s classes. Charlie hadn’t accepted her full scholarship to the University of Colorado for the coursework. She had done it to get away from her parents—and for the proximity to the mountains. The scholarship didn’t mandate that she actually go to any of her classes, only that she pass them. So she spent her time hiking and biking and skiing with classmates, then showed up on exam days.

  There were some courses that intrigued her, although they were all extracurricular and not for credit. Things like rock climbing, kayaking, and self-defense. Charlie was always on time for those, because they were fun.

  The only real problem Charlie had was getting to the hiking trails and ski resorts. She might have been a genius, but she still didn’t have a driver’s license.

  Luckily, Charlie wasn’t the only student who had chosen the University of Colorado for its location. There were always plenty of others who were willing to skip a few days of school for some adventure in the mountains.

  That was how she had gotten here, to Snowmass, even though it was four hours from campus. A few sorority girls had been thrilled to blow off class and give Charlie a ride out to the mountains in return for a free place to stay at a swanky ski-in, ski-out house. Charlie had claimed the house was her uncle’s, when really she had rented it herself, because otherwise she would been stuck explaining how a twelve-year-old girl had enough money to rent a house that cost more than a thousand dollars a night, and Charlie didn’t really feel like doing that.

  The girls were cool, too. This was the second time Charlie had gone on a road trip with them. A lot of her fellow students didn’t know how to behave around her, given her reputation as the tween who was ten times smarter than any of them. They were either condescending, treating her like she was a seven-year-old, or they were weirded out by her, whispering behind her back like she was a circus freak. However, these girls were fun and friendly—and they were rebellious, too. It was one of them, Eva, who had suggested skiing Deadman’s Drop in the first place.

  Eva probably hadn’t thought Charlie would take her up on the challenge, but once Charlie agreed to it, Eva—and all the other girls—had been forced to agree to it as well. They couldn’t let a twelve-year-old be braver than them, could they? They had been acting excited about Deadman’s as they slipped under the boundary ropes and hiked up to it, but Charlie could tell that underneath the bravado they were all nervous and thinking that maybe Eva should have kept her big mouth shut.

  Charlie didn’t think it was such a big deal, though. She had gotten away with far more in her life than a little trespassing.

  She whooped again as she came flying through the couloir.

  Eva and the other girls followed, but much more tentatively, worried about their safety—and Charlie’s, too.

  Charlie fired through a tight gap in the rocks, and the lip of the cliff came into view. It was as though the earth simply ended up ahead. There was a sharp white line where the snowpack stopped abruptly, nothing but bright blue sky beyond it.

  The numbers instantly came to Charlie.

  Her grin jacked up a few notches. She tightened her tuck and barreled straight for the edge.

  Behind her, Eva and the other girls slid to a stop, cowed by the sight of the cliff—and worried that Charlie was heading right for it.

  The girls all knew Charlie was an impressive skier for her age. The rumors around school were that she had grown up skiing somewhere back East, Vermont or Maine maybe. The girls had already seen her handle double black diamond runs with ease and had watched her pull double co
rks off the jumps in the terrain park. But this was different. This was Deadman’s Drop. No matter how good a skier you were, you couldn’t just jump right off a cliff. You had to check it out first, go to the lip and look down, figure out where you were going to take off and land, gather your nerve. You could die on this thing if you weren’t careful—and it sure didn’t look like Charlie Thorne was being careful. If anything, it looked like the girl had a couple of screws loose. Like maybe she wasn’t as brilliant as everyone said; she might have had book smarts, but she obviously sucked at analyzing risk.

  In truth, Charlie had already analyzed Deadman’s Drop far more than any of the girls realized. She had carefully observed the end of the couloir from the ski lift down on the Grey Wolf run. She had assessed the height of the drop and the angle of the ground beneath it and worked out exactly how fast she needed to be going and where she needed to land and then rechecked her math two dozen times and memorized it all. Now all she had to do was enjoy the ride.

  So while the other girls stopped in the couloir and held their breath, Charlie kept barreling forward, apparently unfazed by the sudden drop ahead, laughing like the happiest person on earth. And then she launched herself over the edge, into thin air.

  As the ground dropped away from under her, Charlie was suddenly struck by a pang of fear and self-doubt. What if she had made a mistake in her math? She was five stories in the air above a ski slope. If she made any mistakes now, she could die.

  So she focused on the numbers.

  She saw them in her mind, etched onto the landscape of the earth before her. The numbers were the equations she had worked before, back on the ski lift. They told her how she needed to move, where she needed to land, what she had to do to survive. Better yet, they told her what she needed to do if she wanted to make this look awesome.

  Her fear vanished and her confidence came flooding back. At exactly the right moment, she threw herself into a reverse somersault, whipping her shoulders back, arching her spine, watching the sky rotate in above her, then the cliff, then the horizon—and by then the ground had already rushed up to meet her, so she cocked her skis at forty-five degrees to match the slope, kinked her legs to cushion the impact, and nailed the landing. One second she was falling and the next she was skiing, glowing from the adrenaline surge, rocketing downhill for a few more seconds before dramatically skidding to a stop in a spray of snow.

  The skiers on the Grey Wolf run stopped and gaped in astonishment at the young skier who had just appeared out of nowhere. The skiers on the Elk Camp lift who had witnessed the whole stunt burst into applause. Up in the couloir, Eva and the girls heaved sighs of relief that Charlie hadn’t biffed the landing and killed herself. Charlie allowed herself a moment of grandstanding, flashing a smile to the spectators and taking a bow.

  And then she saw Agent Milana Moon waiting for her.

  THREE

  Milana Moon and Dante Garcia had tracked Charlie with her phone. All phones had Global Positioning Systems in them, and the CIA had accessed that and triangulated Charlie’s location. Dante had assumed they would be heading to Boulder, where the University of Colorado was, but they had discovered Charlie was in Aspen instead.

  Due to the urgency of their mission, they had the use of a jet, albeit an outdated one the CIA had confiscated from some arms dealers twenty years earlier. Agent Moon, among her many other talents, was an instrument-rated pilot.

  They landed at the Aspen airport, which was only a short cab ride from Snowmass. Dante and Milana could both ski, and they didn’t want to sit at the bottom of the mountain for the whole day, waiting for Charlie to come down. Time was too precious in the hunt for Pandora. So they had rented skis and used the GPS to track Charlie more precisely.

  It wasn’t hard to blend in on a ski mountain. Far easier than it was to blend in on a city street, where people could be wearing anything from T-shirts and cargo shorts to three-piece suits. All skiers basically wore the same thing: heavy jackets, ski pants, helmets, scarves, and goggles. The helmets, scarves, and goggles had the added bonus of hiding the agents’ faces.

  They had fallen into the Elk Camp lift line behind Charlie and she hadn’t even noticed. Or so they’d thought.

  The plan was to apprehend Charlie nice and easy if they could: Wait for her to split off from her friends, maybe when she went to the bathroom. Then they’d grab her, badge her, and tell her she was under arrest. Hopefully she wouldn’t try to run, but if she did, they’d cuff her and take her down. It should have been a cakewalk. It wasn’t like they were bringing in a hardened criminal. Just a twelve-year-old girl. If anything, it seemed beneath their rank.

  They had been a little thrown when Charlie and the girls had gone out of bounds, wondering how they could possibly follow them without drawing attention to themselves, but then Dante had talked to a ski bum, who had told them the girls were probably headed for Deadman’s Drop, and if so, that it would dump them right back onto Grey Wolf. The ski bum had even pointed out the exact spot where that would happen. So Milana Moon had posted herself there, acting like a normal skier waiting for her friends, while Dante had gone farther down the run to stand guard by the base of the ski lift, in case something went wrong.

  Which was exactly what had just happened.

  • • •

  Dante knew a great deal about Charlie Thorne, but he had severely underestimated her ability to notice her surroundings, unaware that Charlie had made a point of honing that skill.

  It was amazing how little most people really noticed in the world around them. All federal agents knew that eyewitness testimonies tended to be shaky at best. Most people could barely remember what they’d had for breakfast any given morning, let alone recall details about a suspect they might have seen for only a few seconds.

  But Charlie Thorne was different. She had gotten away after breaking the law, but she didn’t assume that would always be the case. Someday someone would come looking for her. Therefore, she always needed her guard up. She always had to be prepared for trouble.

  Always had to be ready to run.

  So she was constantly paying attention to everyone around her, even here, at a ski resort. She had trained herself to focus on the people in the crowds, to notice what they were wearing, to look for patterns that were too statistically unusual to be a coincidence.

  The woman standing downhill from where Charlie had landed on the ski run had been right behind her in the lift line on the way up the hill. There was nothing particularly unusual about her ski outfit, but this skier was tall for a woman, a few inches above average, and had the same distinct, strong jawline, so Charlie was sure it was the same person.

  Charlie couldn’t help herself; she started seeing the numbers.

  It had been like this her whole life. Even when she was a little kid, well before anyone had tried to teach her math, the numbers had come to her. In fact, no one had ever needed to teach her math; she had simply worked everything out on her own. It hadn’t been difficult. Instead, it had just seemed . . . obvious. It had all come so naturally, Charlie was five before she realized what she was doing was unusual. Until then she’d thought everyone instinctively knew how to add and subtract or how to calculate the volume of a box—or, for that matter, how to understand a foreign language by merely concentrating on its syntax and patterns as it was spoken.

  To understand coincidence, you simply had to understand probability. For example, people were generally surprised if, in a group of thirty people, two turned out to share a birthday. But there was a greater than 70 percent chance this would happen. You just had to do the math:

  So now Charlie worked out the probability that someone who had been behind her in line on the way up the lift would be standing here thirty minutes later, at the exact spot where Deadman’s Drop emptied back out onto the run. To do this Charlie considered a variety of factors, like the number of lifts at Snowmass, the amount of skiable terrain, and the approximate number of skiers there were on the mountain that day.
She calculated a 0.08 percent chance, which was certainly within the realm of possibility, but still slim enough to be of concern.

  But there was one way to definitely tell if this woman was following her.

  Up in the couloir, Eva had finally gathered her nerve to make the jump off Deadman’s Drop. It was hard for Charlie to tell where the suspicious woman was looking, given that she was wearing ski goggles, but her attention—at least for the moment—appeared to be on Eva.

  Without even bothering to wave to her fellow skiers, or to see if Eva managed to land safely, Charlie turned and fled.

  • • •

  Milana Moon didn’t notice Charlie had run for a moment. She was watching the next girl jumping off the cliff, unable to believe someone would risk her life for a stupid stunt like that, thinking there was a good chance the idiot was going to wipe out badly and snap her spine right there in front of everybody. As it happened, the girl did wipe out, tumbling down the slope, her skis and poles flying everywhere, but somehow she was okay. She lay there on the ski run, laughing at herself, then sat up and yelled to her friends, “Well, I really screwed that one up, didn’t I?”

  Then Milana returned her attention to Charlie—only Charlie wasn’t standing there anymore. She was well down the ski run, in a racing tuck, going for speed.

  Milana swore, then grabbed her phone and alerted Dante. “Dagger! It’s Coyote! The rabbit’s on the run!”

  Dante was waiting down the hill, near the base of the ski lift. It was cold, just standing there, and a chill had started to seep into his bones. He was in position to catch Charlie if she ran, but the ground here was flatter, so he’d need ample warning from Milana to get up to speed. Now, as he saw Charlie flying down the hill toward him, he swore under his breath as well. Milana’s warning hadn’t come fast enough; Charlie had gotten the jump on her somehow.

  Milana was coming too, but Charlie had a big lead on her, at least thirty seconds. Dante dug his poles into the ground and moved into the middle of the ski run, blocking Charlie’s path, ready to tackle her if he had to.