She must have drifted—the glassy featurelessness of the horizon made it hard to stay alert. Suddenly Natalya was bringing the Earthmover to a halt beside a towering plateau, a lone knobby white thing that looked like a clenched fist.

“Is this the aquifer?” Park asked, straining to be heard over the rumble of the engine.

Natalya thumped her own shoulder fiercely, signing, Yes. She bent over the Earthmover’s console and began to manipulate the drill over the ice. Park looked around. She couldn’t see how Natalya intuitively knew that this was a place to drill for water. It looked no different than any other place on the tundra. Was it some hidden intuition she had, like the needle of a compass? Or had she been consulting a map without Park noticing all this time?

The HERCULES was still some distance away. Its small body bobbed over the ice like the lure of a fishhook. A high, painful squeal jerked Park’s attention back to the drill; Natalya was hunched over the console, cursing.

“What’s wrong?” Park asked.

“Pneumatic hammer,” Natalya said curtly. “It’s gotten stuck. Some ice in the hydraulic impacts, maybe.” She fumbled with the controls for a while more; the drill screamed in protest until she finally powered it down.

“Can you climb down and take a look?” she asked Park. “I need to figure out this system.”

“I wouldn’t know what to look for,” Park said nervously.

Natalya’s helmet jerked impatiently. “Just see if anything looks caught in the inner mechanisms,” she said. Her voice sounded tight and creaky, like the stretching of a belt behind her visor. She continued to glare until Park opened the cab door and slowly clambered down.

She lifted her faceplate and felt the brutal wind scald her cheeks raw. Park peered helplessly at the coupling of the drill and the cab, then at the enormous cone of the drill itself. It was frozen at full extension, as stuck and rigid as a nail shot through an invisible wall.

“I think I see something,” she shouted.

“What is it?”

Park shuffled closer. “It looks like there’s—” She stopped.

“There’s what?”