Brilliant,” Caleb muttered to himself. “Why did I listen to those kids?”

The cold wind stirred the branches around him, pushing him down a few feet toward the jungle floor. He was about halfway between the ground and the canopy, tangled in vines, a flare sputtering in one hand, the gravity device in the other.

Caleb sighed. Weighing nothing had a disadvantage they hadn’t mentioned—one sudden wind and he was miles away from where he’d started!

He didn’t even know how to turn the device off.

Not that he wanted to at the moment. The jungle below was lit only by the pale blue of the glowflies. The others had warned him about a carnivorous vine down there. That didn’t seem likely, but neither did anything else that had happened over the last two days.

Also, when he’d been up there above the mist, Caleb had thought he’d heard some kind of animal cry down below.

Maybe staying up here in the trees was better for now.

First things first—he needed a free hand to grab branches, but he couldn’t drop the hissing flare. It was his only source of light, and hadn’t Molly said that the shredder birds were afraid of fire? Maybe whatever had let out that cry was, too.

Clutching the gravity device between his knees, Caleb managed to pull his belt loose. Working carefully, he used it to strap the device to one shoulder.

Okay. Falling to his death was no longer a possibility. One less thing to worry about. Of course, his pants might fall down at any moment, but that seemed like a fair trade.

With his free hand, Caleb pulled himself weightlessly upward through the flare-lit darkness, until finally the misty sky appeared above.

He pushed off from the treetops, drifting up into the cool wind.

There was the bonfire in the distance. He could just make out a smaller flame off to the side, waving back and forth.

They’d made a torch to signal him with!

Caleb had to admit—those kids weren’t completely useless.

He waved the flare back at them, wishing he could send some kind of signal. Something that would tell them what he’d seen in the sky—

Those two moons that couldn’t be moons. Sure, their light was steady, not twinkling like a star’s, and Caleb’s sharp eyes had made out craters on their surfaces. But the red moon was almost full while the green one was only a slim crescent—and they were right next to each other.

Even on an alien planet, two moons in the same part of the sky would have to be in the same phase, right? Unless the solar system had two suns.

But that didn’t make sense, either. Why would each moon only reflect one sun? And then he’d seen something that had removed all doubt …

Treetops brushed his feet. He was drifting back down into the canopy, and the wind had pushed him even farther away from the bonfire.

Caleb gave a last wave with his flare, then grabbed for a passing branch. He had to get organized and start making his way back toward the bonfire. This flare wouldn’t burn forever, and he definitely didn’t want to bounce around this jungle in pitch-blackness.

He got his feet under him. If those kids could jump across the treetops, so could he.

With a grunt, Caleb pushed off as hard as he could. A moment later he was in the air, the jungle passing beneath him.

But he’d angled himself too high. The cool wind caught him head-on, stalling his momentum and making the flare sputter in his hand. By the time he drifted back down into the trees, his forward flight had slowed to nothing.

Caleb grabbed on to the thickest branch he could see and gathered himself for an even harder push.

Yes! This time he had it right. He was sailing just above the trees, straight ahead. To reduce wind resistance, he straightened out and put his hands in front of him. Like a diver going into the water.

No, like Superman!

The flare crackled in his hand, spitting back into his face. Caleb imagined the glittering trail of sparks behind him and smiled through gritted teeth.

Anna was right—flying was the bomb.

Too bad they only had one of these devices. Anna was going to want it back when he returned to camp, wasn’t she? The most amazing technology he’d ever seen, and Caleb had let a bunch of kids play around with it.

He wasn’t going to make that mistake again.

His next push carried him too high, and the wind caught him once more.

Caleb swore. He needed to focus on jumping. He could decide later who got to keep the gravity device.

A half-dozen jumps later, he noticed something odd. About a hundred yards to his right was a dark space in the jungle. A low spot in the canopy, as if someone had cut off the tops of all the trees. For some reason, the ever-present blue shimmer of glowflies was missing.

Squinting, Caleb saw that the darkness formed a circle about twenty yards across.

He let himself drift to a stop, keeping his eyes on the dark area as he descended. The circle was so exact, it seemed unnatural.

Was it a camp of some kind?

Caleb felt a wariness come over him. If anyone lived out in this weird jungle, he didn’t necessarily want to meet them in the dark of night. Alone.

But he was more than halfway back to the bonfire, only a mile from the others. They needed to know about this. He had to take a look.

He pushed carefully through the treetops, not flying up into the cold wind. In a few soft jumps he reached the edge of the dark circle.

The trees were different here. Shorter and stumpier, like a whole new species. Maybe this wasn’t a camp at all, just some weird natural formation. Maybe the darkness was only because glowflies didn’t like this kind of tree.

But why were they growing in an exact circle?

And hadn’t Molly said something about circular stands of trees farther out in the jungle? But those were taller, not shorter …

It was only twenty yards across. He could zoom all the way with one push, keeping his eyes open the whole way.

Caleb steadied himself and shoved off gently.

As the perfect circle of darkness opened up below him, his stomach lurched a little.

No, his stomach was lurching a lot.

From his shoulder, the gravity device let out an annoyed little buzzing sound. Like an alarm clock, insistent and pulsing.

“Uh-oh,” Caleb said.

With awesome suddenness, gravity jerked back into existence around him. His full weight came crashing down like a blanket of lead, and a moment later he was falling …

Hard.