He shrugged. “Ten or twenty miles above the mean datum. We can’t say for sure. Mean datum — you understand there’s no ocean on Mars, so no convenient sea level to—”

“You must have some better-resolution images than these. It’s the only visible spot on the planet, for Christ’s sake. Somebody must have pointed the cameras again.”

Priest began to work the keyboard. He found a couple of images which showed her some more detail. She stared at the screen, pressing close to the glass.

“You’re telling me these features are stable? That they aren’t, uh, whirlwinds in the dust storm or somesuch?”

“No way. They’ve lasted since Mariner got to Mars, a couple of weeks ago. We’re undoubtedly looking at some kind of surface feature, here.”

She could see circular markings within each spot. And there was some kind of scalloping. They almost look like volcanic caldera. The mouths of volcanoes.

But why should these features, of all of Mars, be showing up at all? Because they’re in Tharsis. And Tharsis is the highest region on Mars. And why these particular features? Because they are the highest points in Tharsis — therefore the highest points on the planet…

“My God,” she whispered.

“Natalie? What is it?”

Those spots had to be volcanoes, sitting on top of some kind of vast shield system. Big enough to dwarf anything on Earth. Everest was only five miles high; those babies must be fifteen miles at least. So high they were poking above the dust storms; so high they were above the bulk of the atmosphere itself.

“Natalie? Are you okay?”

York couldn’t believe her eyes. She had Priest call up image after image.

At least, she reflected later, the mystery of the Martian geology had taken her mind off Priest.

Saturday, December 11, 1971

NASA HEADQUARTERS, WASHINGTON, DC

After Fred Michaels hung up, Tim Josephson sat in his office, a glass of whiskey in his hand.

The decision was made.

He supposed he ought to be feeling triumph. Exultation. We’ve got what we wanted, by God. Another huge boondoggle, a program that ought to keep thousands of NASA employees gainfully employed for a decade or more.

But the truth was, he felt too beat-up to care.

He was having a little trouble focusing his eyes. He’d been chained to his desk and phone all day, working in support of Fred Michaels’s machinations. And there were still a hundred and one things to be finished up. But, he told himself, there was nothing that wouldn’t keep until the next day.

So he took his shoes off and got his feet up on his desk, and he started dictating into a pocket tape recorder.