She smiled. “What’s this, Ben? Why not just show me the finished picture? More NASA showmanship?”

He raised his eyebrows. “You’re too cynical. Or would be, if I thought you meant it.”

Impulsively she touched his hand. “I’m sorry, Ben.” His skin was warm and leathery.

He grinned at her easily.

Today she was finding Ben, with his intelligence and enthusiasm for the wonderful Mars project, unreasonably attractive. Damn it. I’m not supposed to feel like this.

She concentrated on the pictures.

The upper few lines of the image had been black — just empty space. But then she saw some detail, a curve of gray and white, building up line by line. At first she thought she was seeing the limb of a sphere, but the shape soon looked much too irregular for that.

Phobos turned out to be a rough ellipse, half in shadow, with a battered, irregular edge. It looked much more like York’s preconception of an asteroid than any moon. There were craters everywhere, huge and ancient, some so deep that the impacts that caused them must have come close to splitting the battered little moon in half.

“Natalie, this is more or less the face of Phobos, about half the size of our full Moon, that you would see if you were standing on Mars right now.”

Phobos looked like a diseased potato. Priest was staring at the picture, and its gray and black reflected in his eyes. “This is history, Natalie. Think about it: mine were among the first human eyes ever to see Phobos and Deimos, the moons of Mars. I wanted to show you this, kind of share it with you, the way I saw it.”

She was moved to touch him again, but she resisted the impulse. “Show me Mars, Ben.”

“Sure.”

After a few more minutes Priest had retrieved images of the surface of the planet itself. But the dust storm was still continuing. There was only one place away from the poles where any detail was visible: an area called Tharsis, close to the Martian equator. Here the pictures showed four dark, irregular spots, roughly circular, three in a line running at an angle to the equator, and the fourth a little way away to the west.

She asked, “What the hell can these be?”

“Who knows? I guess we’ll figure it out when the storm clears. The lab staffers are calling them ‘Carl’s Marks.’ After Sagan, see—”

The shapes in the images intrigued her; they were familiar, somehow. If only she could see just a little more… “You say this region’s called Tharsis. Do we know anything else about it?”

“Actually, yes. You’re the geologist, Natalie. You ought to know.”

“Just tell me, asshole.”

“There have been radar studies of Mars since the mid-sixties. This Tharsis region — which is just a bright splotch seen from Earth — looks as if it’s the highest plateau on the planet.”

“Really? How high?”