The multipurpose room was buzzing by the time Elena reached it. The "Camp Universe" banner, along with the posters of stylized beakers, atoms, and galaxies still covered the worst of the mildew stains on the walls, despite three of the campers having tried to jump up and rip them down. The room still smelled musty, with a hint of weed, but at least it was now mixed with Clorox and Febreeze. By Friday, they'd have added the scents of smoke and solder, vinegar and formaldehyde, sugar cookies and slime. The smell of camp.

The best smell.

Some kids ran from one side of the room to the other, whooping and cheering, sending puzzle pieces and legos flying in their path, while others sat against the wall swiping at smart phones. Patrick, the other camp counselor, used the debris from the games and toys as a sort of a game, leading as many kids as he could coerce in congo lines in and around the clutter.

"Okay, everyone!" Michelle's voice called out. The laughter and chatter in the room died down. "Let's take a seat!"

"Hey." A voice right behind Elena made her jump. Dr. Baker.

"Oh, hi!" Her voice came out louder than she had intended. "Um, I got the demos fixed, if you want to see them."

"That's okay. I just had a talk with Michelle, and she asked me to stay for the show."

Her stomach turned a somersault. The show! She should have already been setting up for it, but instead she'd been playing around trying to figure out what was going on with Sam. She hurried toward the back closet, trying to figure out what she was going to tell Michelle.

Michelle came alongside her as she set up the lasers. "Do I need to postpone the show?"

"I'll just be a couple of minutes."

"That's okay. What kept you?"

"I'm so sorry. Got distracted by . . ."

All at once Elena felt ridiculous about the whole thing. No matter what she said, it would just sound like she had imagined the whole thing to cope with her own failure.

Elena turned back to Michelle, who was still staring at her. "I'm sorry, Michelle. I'll get it running as quick as I can. Maybe you can vamp for a few minutes."

Michelle nodded and jogged up to the front of the room, and Elena returned to her lasers. Her hands busied themselves setting them up as quickly as she could, but her mind was still on whether she could trust what she had seen with Sam.

She couldn't bring herself to drop the issue entirely. But if her own eyes couldn't be trusted, she would have to find a way to bring someone else into her experimentation. Dr. Baker was out—he'd just think she was making excuses—and Michelle had enough on her mind. That left Patrick, unless she wanted to take advantage of another camper. She clenched her teeth and worked faster.

The crowd of kids were all gathering to take their seats in front of the platform, where Elena had set up the materials for the show. Elena took a long look around the room. Dr. Baker stood at the back of the room, tablet in hand, staring at her. Michelle slipped out the side door to make her entrance. Patrick sat down in the middle of a group of campers. Sam was in the front row, slid all the way up to the edge of his seat, wide-eyed and grinning.

Part of her wanted to run up and move him to a row further back. Whatever he carried that had messed up the demonstrations in the light room might affect the demonstrations in the show, too.

Her stomach turned. There was nothing she could do about it.

Michelle gave Elena a thumbs-up and a smile from the side doorway, then she closed the door behind herself. Forcing herself to focus on the show, Elena checked her metal case, the box of extra equipment, and the mirrors one more time before she tiptoed to the back of the room. She reached out for the light switch beside Dr. Baker and flicked it off.

Several of the girls in the room screamed, which always happened when Elena turned out the lights. Elena hurried back to the metal case, felt for the switch on the side, and flipped it upwards.

The room filled with a booming prerecorded track of Michelle's voice over techno music: "LADIES AND GENTLEMEN, THE OPENER WILL BEGIN IN TWENTY, NINETEEN, EIGHTEEN—"

The spigots on the edges of the case hissed as they spilled fog into the room. The kids scrambled closer to the stage, many of them switching places several times after they were down, as if it mattered.

"ELEVEN, TEN, NINE—"

Elena's mind kept wandering back to Sam. If he was carrying some kind of device, it had to have a maximum range, but she hadn't taken a measurement of how close he had to be to the shadow box to affect the colors. Maybe that was something she could do the next time she was with him.

On the final five numbers, the kids all counted down together.

Just after "ONE," red, green, and blue lasers flicked on and flashed with the music. Their beams lit up the fog and struck the mirrors just right, and the light paths multiplied into many branching, flashing, shifting paths, extending out to infinity.

The beat of the music kept rising, along with the volume of the kids' cheers, and Elena pulled her colored flashlights out of the box. She flicked them on and swirled them so their bright lights joined the laser beams. In the small room, it was enough to give an effect like spotlights.

Would the colors on these flashlights be shifted if she shined the light close enough to Sam? Or was it proximity to the source of light that mattered? Maybe she could check right now, if she swirled the lights over the campers just right. She glanced over her shoulder at Dr. Baker. Even in the dim light, she could see him staring at her, finger hovering over his tablet.

Not now. She could do more experiments with Sam later, but right now, she needed to focus on the show. Michelle would be counting on her. Elena had already blown her opportunity to impress Dr. Baker, but this show was Michelle's chance to make a good impression, and Elena owed it to her. Owed her that and so much more.

At a peak in the music, the side door burst open for just long enough for Michelle to rollerblade into the room. Elena shifted the flashlight beams over to her, but she didn't need to—her face was well illuminated by the sticks of fire she twirled in each hand. Cheers escalated to screams as she took a lap around the room.

Elena wished she could see the look on Dr. Baker's face. If a single metal briefcase designed to control fog, lasers, and speakers with music timed to the lights didn't sell him on Elena's engineering abilities, he would at least see the value in Michelle's many theatrical specialties. He'd see what made Camp Universe worth funding.

Michelle completed her trip with a leap onto the front platform, and she skidded to a stop, her arms raised and the fire flickering, casting an eerie glow into the smoke around it. That trick always made Elena a little nervous, but they were well practiced—Michelle would be fine as long as Elena gave her enough light with the flashlights.

Michelle lowered the torches into a bucket Elena had prepared on the platform, and wisps of real smoke joined the clouds from the party case. She bent down for the little plastic tube Elena had left at the front corner of the platform and slipped the end between her teeth. She took a matchbook out of her back pocket and lit a match, holding the tiny flame a few inches from her lips. When she breathed out, jets of flames burst from the tube. Screams and cheers erupted from the crowd.

Elena let her breath out. The most dangerous part was over. She glanced over her shoulder. Dr. Baker was smiling—just barely, but still.

Elena kept the light from one flashlight on the stage, but now that they had succeeded in impressing their evaluator, she couldn't see the harm in using one flashlight to skim over the campers until she found Sam, still in the front row. Nothing had failed so far, though she couldn't tell if the beams were shifting in color when they drew near to him. She swung it more slowly, bringing it nearly to a stop over Sam. Too hard to tell: the beam was too spread out and divided among the campers' heads, she couldn't identify its color at all.

A lull in the cheering pulled her attention back to the opener. Michelle was waving to get her attention. Cheeks growing hot, Elena shifted the flashlight beams back to right around Michelle's face, just angled such that they would give her light but not blind her. She had to stay focused.

The last demonstration was a delicately balanced chemical reaction—gummi bears in test tubes of potassium chlorate. Correct proportions of the chemical would cause the liquid to glow, spark, and fizz; bad proportions would fizz too much or too little. A really bad balance could spray the campers with molten gummi bears, but Elena would pretty much have to mess it up on purpose for that to happen.

Michelle picked up the package of gummi bears and dropped one into the first test tube.

Nothing.

Still, the kids waited with held breath. Elena couldn't blame them—they knew something was supposed to be happening, but not how long it was supposed to take to happen.

Michelle set down the package, leapt to her feet, and shouted, "LADIES AND GENTLEMEN, FUTURE SCIENTISTS AND ENGINEERS, WELCOME TO CAMP UNIVERSE!"

Their applause was scattered this time, and there were no cheers, only a few cries of "Aww!"

Elena's stomach churned—had she somehow managed to forget to refill the test tubes? The whole morning was a blur.

Elena set down her flashlights and tiptoed around the campers to the front of the room. Getting the reaction to work could save the show, and if she couldn't, it would hardly be more anticlimactic than it already was. She could at least try—she owed Michelle that much, since Dr. Baker might not have even stayed long enough to see the show if things had gone better in his tour with her.

Elena peeked into the test tube. The level of the potassium chlorate looked right, but the gummi bear just floated in the liquid as if it was water.

She let her eyes fall closed. It was water. It had to be—it was the only explanation that made sense. Maybe she'd managed to switch out the bottles in her stress over the evaluation this morning, though that seemed like a stretch. More likely, Patrick had spilled the chemical and hadn't wanted to let her know, so he'd tried to fix it by refilling the test tubes.

If it was water, she could fix it. She hurried over for the bottle of potassium chlorate at the back of the stage, and ran back to pour a bit of the chemical over the gummi bear. She wouldn't push it to the limit, but a little would at least make it fizz.

Nothing, again. She reached down for the package of gummi bears and dropped a second into the test tube, then a third. Still nothing.

How was it even possible that the chemical reaction wasn't working? She touched the test tube—it was room temperature—and picked it up out of its place, holding it up to inspect it from beneath.

That's when she became aware of the eyes on her.

Elena swallowed hard and slowly looked down at the crowd. Everyone stared at her, including Dr. Baker's. The techno music still boomed, the lasers still flashed, and the fog filled the air, heavy enough now to seem motionless.

Her cheeks felt hot. What had she been thinking? She could have left well enough alone. The ending had been anticlimactic, but it hadn't been painfully awkward.

Her gaze fell on Sam. His eyes shimmered in the flashing lights, and he mouthed I'm sorry before burying his face in his hands and running away.

The test tube in her hand exploded in a flash of light and sparks.

Elena dropped the test tube. She jumped back, just avoiding the splash of chemicals and glass, then she glanced over the campers. Most of them had ducked, a couple squealed, but none cried out in pain.

She let out her breath. At least there was no real damage done. She took one step toward the edge of the stage when a girl in the back row screamed, pointing above Elena's head.

The "Camp Universe" banner above the stage was on fire.

Elena froze. Michelle darted for the fire extinguisher beside the platform, Dr. Baker flicked on the lights in the multipurpose room, and Patrick ushered the kids back from the banner.

The foam from the fire extinguisher kept blowing the banner out of reach, so it took several seconds for the flames to die down. By the time the fire was out, all the remained of the banner was a half-charred, white-speckled Camp.

The booming techno music from Elena's case still played. Elena blinked and forced herself to snap out of her trance. She ran over and flipped the switch on the side of the case.

Aside from a bit of whimpering, the room was silent. Elena let her breath out and glanced from Michelle, who watched the kids as she put away the fire extinguisher, to Patrick, who held several of the kids under his arms, to Dr. Baker, who was looking down and shaking his head.

Elena exchanged a nervous glance with Michelle. She wished they could talk before going into their next conversation with Dr. Baker, but she doubted they'd have the time to strategize.

Dr. Baker stepped forward, between Michelle to Elena. "Can I speak to the two of you?"