"Miss Elena, my shadow is broken."

Elena looked down from the ladder where she was straightening the Camp Universe banner. A red-haired, freckled boy looked up at her, bright green eyes wide with expectation.

She swallowed hard—the evaluator would be here any minute. Elena squinted to read the boy's name tag in the low light of the classroom. "Hey, Sam, maybe Miss Michelle can help you with the shadow box, I'm a little busy."

"But you're the technician. And there's something wrong with my shadow!"

Elena glanced back and forth between Sam and the door to the classroom. She hadn't checked the last of the camp decorations in the multipurpose room, and she hadn't had a chance to look in the mirror since testing the electrostatics demos this morning. But if there really was something wrong with the shadow box, it was more important for her to fix that. Besides, Sam looked really frantic. "Okay, fine. Show me."

Elena followed as Sam led her over to a small area against the front wall of the classroom. Red, green, and blue spotlights, carefully adjusted to the right levels, mixed to make white light on a whiteboard. Stepping in front of the lights cast multi-colored shadows on the wall.

A few kids stood waving their hands in front of the colored lights, some dancing with the background music and giggling as they watched their shadows step in time as well. "What's wrong, Sam?" Elena asked.

"The sign says we're supposed to have a yellow shadow, a magenta shadow, and a cayenne shadow. But I don't have a cayenne shadow."

She laughed a little. "Cyan. It's kind of like aqua."

"Well I don't have a aqua shadow. And my magenta one isn't trying very hard, neither."

She sighed—she had double and triple checked the color balance before class. "Go ahead and stand in the shadow box."

He trudged over to the whiteboard, and three colored shadows stretched out behind him. The yellow one was fine, but the magenta one was a little too red, the cyan one a little too green. Her coworker Patrick had probably been playing with the equipment. She knelt down to adjust the brightness of the blue light. "How about now?"

"Um, it still looks funny."

"Hang on, I can fix this." She dodged her way through the dancing campers to the light bulbs.

She picked up the dimmer for the blue bulb. Slowly, she turned up the brightness, then she turned back to the whiteboard, stepping past the dancing campers again. The light still appeared too red.

She set down the dimmers, straightened up, and looked back at the too-red whiteboard.

And watched it shift to blue.

She blinked—it must be some kind of afterimage, or her eyes were playing tricks on her. She needed to lay off the espresso. "Sam, do you see your cyan shadow now?"

"Yeah. But my magenta one is blue."

Not a trick of the eyes, then. Something was wrong with the dimmers—really wrong. She made a mental note to keep her evaluator away from the shadow box. She jumped to her feet. "Look, Sam, I have no idea what's going on here, and I have to go meet with—"

"Excuse me, are you Elena Holmes?"

Elena whirled around. A tall man in a full suit stood behind her, tablet in one hand and coffee cup in the other.

Her cheeks felt hot. "I, uh, yes." She held out her hand for him to shake before realizing his hands were full and pulling hers back.

"Dr. Baker. This won't take long. The sponsorship department just wants me to take a look around and see what you do."

She nodded, though her teeth clenched. She was supposed to meet him in the multipurpose room, away from the chaos of the campers.

"So why don't you just tell me a little about what's going on right now?"

Elena took a deep breath. "Um, so, this is our light activity lesson. I set up these curtained stations so kids can explore different light phenomena, and the other camp counselor, Patrick, covers all the tables and floors with tarp so we don't—"

Sam ran up to her and pulled on her shirt sleeve. "Miss Elena, my shadow is still broken."

She forced herself to smile. "Maybe you can ask Mr. Patrick—"

"Miss Michelle said to ask you."

"Look, Sam, I'm talking with a grown-up right now—"

"Oh, it's no problem." Dr. Baker hardly glanced up from his tablet. "Go right ahead."

She pressed her lips together. Her evaluation wasn't supposed to involve working with kids. She wasn't hired for that: she liked kids, but she wasn't good with them. Somehow, this didn't feel like the right time to mention that. "Okay, Sam, let's go stand in the light."

Sam followed her over to the whiteboard, and the kids who were already there stepped away and continued dancing.

She waved her hands—the cyan shadow was gone again. What the . . .

"Problem, Elena?"

"No, I just . . . for some reason . . ." On an ordinary camp day, she would have shut down the shadow box station and taken the equipment aside to be inspected, but she didn't want to have to do that in front of Dr. Baker.

Sam sat on the floor in front of the whiteboard, sulking. Dr. Baker glanced from Sam to Elena, so she took a deep breath and knelt down to Sam's level.

"Are you okay?"

"Yeah." He hung his head lower.

She started to stand, but Dr. Baker was still staring at her, so she turned back to Sam. "Um, what's wrong?" she asked.

"I can't do any of the science."

"It's not your fault, the demos are sometimes—" She winced. She couldn't say the demonstrations she had built were finicky, not in front of her evaluator. Besides, they usually weren't finicky. "Um, you could try something else. There's lots of stations."

Sam shrugged.

"Do you want to play in the mirror box?" That would keep him occupied while she finished her evaluation. Depending on where someone stood in the box, they could see four, five, or six images of themselves looking in different directions, or an infinite number stretching off into the distance.

Sam shook his head. "It's too crowded in there."

"Well, what if you went over to the optics station?" The largest canopy, in one of the back corners, held a table set up with optical equipment: light beams, mirrors, lenses, refractors and beam splitters. This was a space for the most patient campers, but it would keep him busy.

"I already tried. I can't get the lens to work."

Now she was starting to feel sorry for him. "Okay, well, did you read the instructions?"

He nodded and stood, and she followed him over to the optics station, which was all but deserted. "So, I'm supposed to put the flashlight here, and the smiley face stencil here, and the lens here . . . then there's supposed to be a smiley face on that wall."

Elena scanned over his measurements. They were perfect. "Hm. Can I take a closer look?"

Sam nodded, stood, and took a step back. Elena knelt down and lifted the lens, blew away the dust, and placed it back where he had had it. The smiley face appeared on the wall. "Should be working now." She picked up the lens and handed it to him. "Give it a try."

Sam wrinkled his nose and took the lens. He set it back in the exact same place, but no image appeared. He sighed, resting his elbows on the table and his chin in his hands. "Well, at least I learned something today."

"What's that?"

"I'm still really bad at science."

"Hey." Elena placed a hand on his arm. "You're not bad at science."

"Yes I am! I can't get anything to work."

Elena bit her lip. She could just make out Dr. Baker frowning out of the corner of her eye. "Hey. What if we went to take a look at something that works for everyone? You don't even have to do anything, just look at it."

Sam shrugged.

"Come on, let's go to the colorblind room. It's my favorite." The monochromatic room never failed. She'd had to place the black curtain very carefully around this section to filter all light pollution, and flooded the room with bright yellow light from a single neon sodium lamp. A neon sodium lamp could only produce one frequency of light, so anyone in the room was colorblind until they left.

Elena pulled aside the curtain and allowed Sam, then Dr. Baker to enter before she stepped inside. A few kids stood chatting with each other, their faces gray and their lips shiny in the bright yellow light. She walked past the bowl of jelly beans and the table of household items, heading straight over to a stack of posters.

She flipped through the papers to find her favorite. It was a picture of a candy shop with multicolored candies, and a caption that read, "Find the blue candies." In the yellow light of the room, blue was the most impossible to see.

"Here." Elena knelt down beside Sam and handed him a flashlight. "See if you can find the blue candies without the white flashlight. Then you can shine it and see if the picture looks different."

She left the poster in Sam's hands and stepped back to watch beside Dr. Baker. "Have you been in a monochromatic room before?"

"Of course," he said. "But I'm not sure this is a pure sodium neon lamp."

Elena blinked. "I tested the spectrum myself. It works."

Dr. Baker pointed to the poster in Sam's hands.

"I don't get it." Sam's fingers kept flicking the flashlight on and off even as he looked up from the picture to Elena's face.

Elena frowned. "The blue in the picture just looks black until you turn on the flashlight."

Sam squinted and cocked his head.

She walked over and knelt beside him once more. "Turn off the flashlight."

He did, and Elena blinked a couple of times for her eyes to adjust to the monochromatic light.

Her breath caught in her throat. The blue stood out as clear as day.

She'd seen this picture a million times in the sodium neon light. The blue was supposed to look black. It always looked black. She stood and tapped the sodium neon bulb. It must have been broken in some way, but she couldn't find the malfunction.

Elena knelt down to the floor and crawled along the edges of the tent, feeling where the curtain met the floor—a leak would let white light through, which might explain why the blue was visible. There were no leaks.

Sam's voice piped up. "Are you okay, Miss Elena?"

All at once she remembered where she was. She glanced up from the floor. Both Dr. Baker and Sam were staring at her.

She cleared her throat and jumped to her feet. "I'm fine."

"I think—" Sam's voice cracked— "I think I broke your demo."

"It's—but—no, you—"

He groaned and stormed out of the room. "I'm not good at science," he called back.

Elena started to go after him, but Dr. Baker stood beside the lamp, swiping away at his tablet. The evaluation wasn't over. "Do you want to see another station?" she asked.

Dr. Baker raised one eyebrow. "Do you have one that works?"

"They all—" She stopped herself. It was no use trying to convince him they'd been working earlier this morning, and last week, and all of last summer.

Dr. Baker shook his head and left the canopy, holding it aside for Elena. She took one last glance back at the poster on the table. The blue candies were black again. She breathed in to say something, but stopped herself. There was nothing to say.

"Why don't you take some time to fix your equipment? I need to send a message to headquarters. I think I'm going to stick around a little longer than I'd planned." Dr. Baker turned to leave the room before she had a chance to reply.