A few hours later, the canyon floor sloped up and the rock spire formations began to recede. A huge plain opened up before us, smooth and black. A not-so-ancient lava flow. Without the hoodoos obscuring my view, I could see that we had almost reached the foot of Elysium Mons—the central volcano, and the tallest of the three. I hadn’t realized how close we were to where I’d lived as a kid. But everything looked so different. The canyon with the hoodoos wasn’t there in my time—thousands of years of wind and the briny Martian water must have worn it completely away.

“How much farther do you think it is?” I called to Nadin.

“I don’t know.” She looked down at the oxygen tank at her hip. “Eliin said this would be enough. We must not be far now.” She shielded her eyes, looking up at the towering peak. “Do you see any signs of life up there?”

I shook my head. “Nothing.”

Her hood slipped again, and she pulled it back up. “What if this was a trick? What if the Liberator sent us out here just to get rid of us?”

“Of course not,” I said, my voice more confident than I felt. “Come on. Tuupa and Thork know where they’re going. We’ll be there in no time.”

Without the buffer of the rock spires, the wind was harsh and freezing. I pulled my burlap cloak tighter around myself, but it still nipped at my ears and dried out my eyes. Every so often, Tuupa would glance over her shoulder at me, growling reassuringly as if to say, “We’re almost there.” But the mountainside looked as barren and dead as ever.

Another hour passed when Nadin slowed Thork’s pace, looking up at the red-tinged skies.

“What is it?” I asked.

She pointed. “Do you see those clouds?”

I nodded. A thick bank of red-gray clouds was creeping toward us from the south. “Do you think a storm is coming?”

“I hope not.” She patted Thork anxiously. “Let’s try to reach the mountain before then.”

Thork and Tuupa hurried forward, their muscular legs pummeling against the ground, their spines a sharp horizontal line from their heads to the tips of their thick, powerful tails. I watched the storm clouds warily—they seemed to be bearing down on us fast. I hoped it was just an optical illusion.

We were at the foot of the mountain now. The peak was high, but it was far wider than it was tall. The slope was gradual but seemed to stretch on forever. Once we’d reached it, it seemed that the mountain was all there was to the world.