“Solar power?” I suggest tentatively. “The suns’ light gets trapped inside the glass?”

“Maybe.” Elder turns the cube over in his hand as if expecting to find an on/off switch.

“Those square depressions in the windowsills,” I say, rubbing my knee where I scraped it against the windowsill as I was escaping. “The ones we thought were meant for idols or something? They’re the exact size of the cube.”

Elder runs his hands over the smooth surface. “Put the cube in the window in the morning so it charges with light all day and glows all night. Genius.” He looks up at me. “Remember the square light in the ceiling of the communication building at the compound?”

“You think it was something like this?”

Elder nods. “I bet the top is exposed on the roof so it can charge. Maybe all the electricity—the computers, the communication bay—runs on solar energy.”

Already, the light in the cube is starting to fade. It had barely been charged in the sunlight at all before I stuffed it in my sleeping bag this morning.

“The one piece of information that’s been consistent since we’ve landed,” Elder says, “is that the FRX found valuable resources here on Centauri-Earth. It’s the first thing anyone ever talks about with this mission, even your dad. What if this is the valuable resource?”

I nod. “It makes sense,” I say. “Solar energy is free. Enough of these would light up a city.”

“And if it breaks . . . ” Elder tips his hand over but doesn’t drop the cube. “Boom.”

He’s thinking the same thing as me: this is what killed Kit. Whoever made the cube can also make bullets. The cube didn’t break when it hit the stone floor, but if they found a way to make the bullets break on contact . . . well, that would explain why it looked as if Kit’s chest exploded.

“I think there’s something else,” Elder says.

He explains to me his theory that the one thing linking the victims together is Phydus.

“But I don’t know how we can prove that this is about the drug,” he says. The glass cube is barely glowing now, making the room filled with more shadows than light.

I think about the emptiness in Dr. Gupta’s eyes as the ptero ate him. The way Lorin died without a mark on her. The samples of their blood in the lab in the shuttle.

And then it hits me.

“I know how to prove it.”

36: ELDER

I take the glass cube with us as Amy leads me to the shuttle, keeping it covered until we’re in the forest. Amy has her gun, but I’d like to be able to see if an enemy is approaching us—ptero or alien.

As we trudge through the forest, I can’t help but think about how comfortable Amy’s sleeping bag looked, how nice it would be if it—and she—stayed in my building tonight rather than returned to her parents. These thoughts soon evaporate, though. The forest feels more dangerous now. When Amy and I snuck out to the compound last night, we did so with the belief that the deadliest things on this planet were the monsters in the sky. But now we know something else is out there, and the knowledge makes the shadows feel ominous, deadly.

There’s a soft glow under the shuttle as we approach, and I know Amy is right: glass on this planet somehow traps solar energy. I think bitterly about the lead-cooled fast reactor in the engine room of Godspeed, the flashing red light that means it’s in meltdown. If there was some way to make the energy in the glass on this planet fuel the ship . . .

If we could do that, then . . . what? Bartie could wait to distribute the black patches for another few years? They’re trapped, and just like Amy warned when we left them there, there’s nothing for the people of Godspeed to do but wait for death.

I have to save them.

Amy leads me to the lab aboard the shuttle. As we pass the armory, I consider pausing and selecting a gun for myself, but I keep walking. I’d rather have answers than weapons.

“Mom’s been having me help her with her experiments,” Amy explains as she picks up a long-stemmed cotton swab and walks over to the Phydus pump. Its wires are still exposed and broken from my hasty dismantling of the pump so long ago. Amy lifts the panel that covers the spout where Eldest used to deposit Phydus. Some of the sticky, viscous liquid is still inside, and although it’s dried into stains on the edge of the valve, Amy jabs the cotton swab deep into the pump and extracts it, covered with the dark syrup.

Amy moves quickly to make sure the Phydus doesn’t drip off the swab until she can scrape the liquid into a cup. Then she places the cup into a machine.

“Analyte generator,” Amy says as the machine works. “It basically just makes a test so that we can see if something has Phydus in it.”

The machine dings.

“Done,” Amy says. “Now we need a sample to test.” She opens a small refrigerator door and pulls out sample cups of blood. I read the labels one by one: RAJ GUPTA, JULIANA ROBERTSON, SHIPBORN FEMALE, SHIPBORN DOCTOR.

“They didn’t even bother with Lorin and Kit’s names,” I say bitterly.

Amy ducks her head. “I’m sorry,” she says.

She tests Lorin’s blood first. “We know she was wearing a med patch, so it’d make sense for the results to test positive for Phydus,” she says. We wait for the machine to finish analyzing her blood, then read the results together.

“That’s a lot of Phydus,” I say, staring at the report. “One med patch wouldn’t make her have that much.”

Amy frowns. “That much Phydus would . . . ”

“It would kill her,” I say.

“Lorin’s body wasn’t marked by attack.” Amy looks at me, realization dawning. “I saw her, before they buried her. She looked like she was sleeping.” Amy’s eyes fill with a mix of horror and disgust. “She looked the same way Steela did, the woman Doc overdosed with Phydus.”

“Test the rest of the blood,” I say.

Dr. Gupta’s is positive for Phydus—not as much in his blood as in Lorin’s, but enough to have made him silently accept being eaten alive by a ptero. There’s Phydus in Juliana Robertson’s blood too. I wonder if it was the Phydus that killed her or if it was the ptero attack that did it. Maybe she had the same fate as Dr. Gupta, without a bullet in her brain to end it quickly and mercifully.

“None in Kit’s blood,” Amy says.

“Then it was the bullets—or the sun glass, or whatever it is these aliens use—that killed her.” But that was just Kit. The others— “Amy, how did this planet get Phydus? It was developed on the ship. The ship that never landed here.”

“Is there a chance the Plague Eldest landed? Maybe he landed and then went back up?”

I shake my head. “Godspeed was never meant to do more than reach Centauri-Earth. If it landed, there’s no way it could have gone back into orbit. There’s enough fuel reserved for deorbit, no more. And before you ask—the shuttle, once it’s detached from the ship, can’t be reattached. You heard the way the metal broke. And there’s no more fuel for that in the shuttle either. Godspeed always had only a one-way landing process.”

“Then . . . how?” Amy asks.

Neither of us has an answer.

37: AMY

The glass cube is completely dark by the time we leave the shuttle. We’re both lost in our thoughts and on edge. Every noise in the forest makes us jump, every shadow makes us flinch.

Which is why I nearly scream when we get to the edge of the colony and someone says, “Amy!”

“Chris!” I say, clutching my heart as he steps out of the shadows. Elder rolls his eyes.

“What are you two doing out here?” Chris asks, looking at us both.

“None of your business.” Elder steps in front of me as if he’s going to protect me.

Chris ignores him. “Let me walk you back,” he offers, readjusting the rifle strapped to his shoulder.

“No need,” Elder growls.

I put my hand on Elder’s arm. I know he’s not happy about this turn of events, but I’m also not ready to battle my father if Elder’s looking for a fight. “You go back to your building,” I say. “Chris can walk me back to mine.”

“But—” Elder starts, but I shake my head at him. He looks away, then strides up the paved path toward his own home.

“I don’t think he likes me very much,” Chris comments as Elder storms away.

I bite back a laugh. “No,” I say. “But that’s okay. He’ll come around.”

Chris looks doubtful.

Instead of taking me straight back to the closest building—which would take less than five minutes—Chris veers to the right, skirting the meadow at the edge of the colony. “Amy, there are things I want to tell you . . . ” he says. He runs his fingers through his hair—much like Elder does when he’s frustrated—and then stops abruptly, looking up at the stars.

“Yes?” I prompt.

He doesn’t speak for a long moment. “I . . . I think I can trust you. You’re not like your father.”

This comment leaves me speechless. Is Chris saying that my father’s untrustworthy? Emma said as much earlier, but it feels different coming from Chris, who has practically been my father’s right-hand man since the first expedition to the probe.

The probe. Chris was there when Dad found it.

“I know what you’re going to say.” I ignore Chris’s expression. “Elder and I . . . we’ve already found the compound. We know what’s out there.”

Chris looks genuinely startled and can’t seem to form any words in answer to me.

“I don’t know why Dad’s keeping it a secret . . . ” I continue. I look up at Chris’s uncannily bright blue eyes. “But thank you.”

“Thank you?” Chris echoes, still at a loss for words.

“For trusting me enough to tell me,” I say. I touch his elbow, not speaking until I have his full attention again. “I mean it, thank you. It really means a lot to me.” Telling me about the compound against my father’s wishes would be the kind of treachery my father would never forgive. But it also seems as if Dad’s hiding something even more important than Elder and I have realized. Something both Emma and Chris aren’t happy about.

“Why is Dad keeping the compound so secret?” I ask. “Does it have something to do with the aliens?”

Chris’s eyes round in further surprise.

“Don’t look so shocked!” I say, laughing softly. “Elder and I figured it had to have been aliens that attacked Kit—that killed off the original colony.”

I cast my eyes up to the buildings behind us, nothing more than a dark outline against the bright stars.

Chris touches the side of my face, his fingers sliding down my cheek and twining in my hair. My breath catches in my throat as he looks down at me with such intensity that I can barely think straight.

“You, Amy Martin,” Chris says, “are one of a kind.”

He pulls me closer and, like a magnet that can’t resist metal, I’m drawn to him.