But between him and the airlock lay a fifty-yard stretch of unstable permafrost, and the wind was picking up.

As he rounded the bend of the canyon wall, the silhouette of the relay station appeared—Checkpoint 1. It sat perched on the edge of the abyss like a waiting gargoyle. If he could reach the terminal there, he could upload the drive and reset the system.

He forced his boots to move, the magnetic locks clunking against the metallic catwalk of the exterior ridge. Below him, the lights of the Valles Marineris colony were dimming as the power grid failed. "I'm moving," he rasped, his voice catching on the dry air.