“Twenty-four thousand feet,” Stone said. “Coming up to throttle down. Mark.”

The primary guidance program would take the descent engine down to 60 percent thrust. Gershon could feel the thin vibration subsiding smoothly. Right on schedule. “That felt good,” he said. “Better than the sims.”

“Twenty-one thousand. We’re still go. Apart from the radar lock. Velocity down to twelve hundred feet per second.”

Twelve hundred. Aircraft speed. Gershon took hold of his controls. I’m flying in the atmosphere of Mars. He looked out of his window. The stars were all washed-out, and the sky was a tall dome of brown light. And he could see the ground. It was a rumpled landscape that slid underneath him. Visibility was good: the contrast, the shadows cast by the low morning sun, made everything stand out.

Challenger was approaching the landing site in a broad sweep from the southwest, so it was flying over the ancient, cratered terrain of the southern hemisphere. It was almost like a lunar landing sim, with craters piled on craters, some so old and huge they were almost obliterated by newer strikes. But these craters had sand dunes rippling across their floors, and there was one big old fellow whose walls looked like they had collapsed under a stream of running water. The Moon, it ain’t.

The landscape was desolate, curving tightly, forbidding. It was an empty planet, no ground support… No runway lights down there, boy. On the other hand, nobody shooting at your ass, either.

“Seven minutes thirty,” Stone said. “Sixteen and a half thou. Coming up on high gate. Still no lock.”

“High gate” was the point in the trajectory where Gershon should be able to see his landing site for the first time. He peered ahead.

The designated landing site was just to the north of an escarpment at the mouth of an outflow valley. The valley, according to York’s descriptions, would look like a dry riverbed. Gershon had studied the site from orbiter photographs and plaster-of-paris models until he knew it like he knew his own apartment.

But coming in now, with the sun low, and the ship still tipped up at more than fifty degrees, and the light glinting off his little triangle of a porthole…

Nothing looked like it was supposed to. The land was complex, tortured, its nature changing rapidly. Every shadow was deep and black, and the ocher-colored surface features seemed to leap out toward him, the vertical scale magnified by the contrast.

“Fifteen thousand,” Stone said. “Still no lock.”

Shit.

“Okay, Ralph, let’s go over the abort procedure.” Stone sounded resigned.

Goddamn it to hell, he’s given up.

“We pitch over, activate the ascent program… countdown to mission abort starts at eight thousand feet—”

“No. Don’t abort,” Natalie York said suddenly.

Stone looked at her. “Huh?”

“Don’t abort. We may be flying over a radar-dark area.”

“And what,” asked Stone drily, “is a radar-dark area?”