Bradley had strode up alongside him and was peering through her binoculars, but a glance in her direction revealed she hadn’t been focused on the notch. Instead she was scanning the ground. As Scarborough guessed he should have been doing.

“I don’t get it,” she said.

“Get what?”

She looked at him.

“The rover’s tracks,” she said, and handed over the binocs. “Check them out for yourself.”

Scarborough readily obliged, his gaze following the parallel bands of Scout’s wheel marks. They coursed across the open sand in a fairly straight line for what he estimated was a hundred yards, and then swung away toward the notch. That didn’t surprise him. Rather, it seemed to confirm that the probe had been operational when it reached the area, since one of its selective tasks was to explore, image, and collect geologic samples from the notch’s interior. Why had Bradley sounded so puzzled then?

It took a minute before he understood.

Just when the tracks got to the flat apron of the notch, they evaporated. And insofar as Scarborough could judge from his vantage, did not resume at any point beyond.

“Crap,” he said. “Seems we’re about to lose the trail.”

“Yes,” she said. “What do you make of it?”

Scarborough was thoughtful. “I don’t know. Could be it was scrubbed clean by wind.”

Bradley’s silence betrayed her skepticism. Scarborough couldn’t blame her. His explanation had been pretty feeble. There was a significant distance between the spot where Scout’s wheel marks stopped and the entrance to the notch, and the gusts in this section of the pass were blowing a trifle less vigorously than in the last stretch his party had covered. It seemed improbable that the trail wouldn’t continue further on. At the very least it should have left some partial remains. But from where he stood, the rover might as well have been swallowed up by the sand.

Scarborough’s view through the glasses clouded from his breath, and he rubbed the steam off before it could freeze. Then he wiped his snow goggles. Not that he needed to bother. He knew what he had seen. Or hadn’t seen, to put it more aptly. Neither the wheel marks nor the rover would materialize at his command. That magic trick exceeded a Coke-bottle genie’s abilities.

“What’s happening?” Payton demanded from over his shoulder. “Why are we standing here?”

Scarborough turned to him. The guy was like a perverse talking doll with about four lines of nastiness recorded on its voice chip. Still, he was owed a straight answer. Scarborough would have preferred one that was simultaneously optimistic, but didn’t know how to pair his goals. He chose between them, braced for Payton’s reaction.

“Scout’s trail wipes out short of the notch,” he said. “From what we can see, it doesn’t pick up again.”

Payton looked at him.