I still couldn’t quite believe what had been through that archway. Even knowing that ancient Mars had been inhabited, I never would have anticipated anything like this. Or that I would get stuck here. It didn’t feel real. I kept expecting to wake up back on Mars, in that cave, with Joseph Condor looming over me and telling me I’d slipped and hit my head or something.

I wasn’t sure what would be worse, honestly.

I leaned forward in my saddle, peering at the tunnel ahead of us. Sunlight streamed in through various holes in the ceiling, casting the sandstone walls in a vibrant orange glow. We were coming up to yet another fork in the passage.

“It’s a good thing the gurzas know where they’re going,” I said, looking over my shoulder at Nadin, “because I sure as heck couldn’t figure it out.”

Nadin didn’t respond. She’d been weirdly quiet ever since we left Eliin’s. Several strands of hair had fallen out of her braid, and she hadn’t even tucked them back in like she was always compulsively doing. As her gurza passed under a shaft of light, I could see that her face was noticeably paler, and a thin layer of sweat beaded on her forehead.

“Nadin? Are you okay?”

She blinked at me, like her eyes were having trouble focusing. “I don’t feel well,” she said.

I frowned, tugging on Tuupa’s reins to slow her down. Thork and Nadin drew up beside us. “What’s wrong?” I asked. “Do you have a fever?”

“I don’t know. The System always regulated my body functions before. Without it, I feel…” She sighed, slumping forward and resting her face against the back of Thork’s scaly neck. “I feel like I’m going to die.”

My pulse jumped. Ordinarily I’d roll my eyes at a dramatic sentence like that, but Nadin looked like she really meant it. “Do we need to go back? Maybe Eliin can help—”

“No,” Nadin protested. “We can’t tell her. She was already suspicious. If she finds out we lied to her…”

“Then maybe we should stop for the day so you can rest.”

“We can’t stop! I have to rescue Ceilos.”

“Yeah, Nadin, but you’re not going to be any help to Ceilos if you’re dead.” The word made me feel nauseous. Taking her earpiece off couldn’t actually kill her, could it? I didn’t believe that could be possible, but she looked so weak. Not like Nadin at all.

“I’m fine,” she insisted. “Let’s keep going. Just a little while longer.”