"What do you think, Lucy? You think I want him workin’ in a store, waitin’ on tourists from Beverly Hills or New York? You think I want him wastin’ away his life in some dumb-ass pueblo raisin’ sheep and drinkin’ beer the rest of his life?"

"He’s shown an aptitude for science," Jerry said.

"Then let him study science! They got fine scientists at Albuquerque. All kinds of geologists and whatnot."

Geology. Jamie had spent long hours collecting rocks in the arid hills and arroyos. Al had taken him up to Colorado to see the Mesa Verde cliff dwellings, and out to Arizona for the Grand Canyon and the big meteor crater.

"Some of the finest scientists in the world are at Berkeley," Lucille was saying stiffly. "In the physics department alone…"

Al interrupted her. "Hell, here we are talkin’ about the boy’s future as if he wasn’t even here. Jamie! What do you think about all this? What’ve you got to say?"

Jamie remembered the Grand Canyon. That vast chasm carved into the Earth. The colors of the different layers of rock, layer after layer. The whole history of the world was painted on those rocks, a history that went incredibly farther back than the span of time human beings had existed.

"I like geology," he said. "I’d like to study geology, I think."

More than an hour had passed since they had started off. Jamie was fingering the bear fetish in his coverall pocket as the rover climbed the slope of a ridge, laboring up a steepening grade that was strewn with smallish rocks and pebbles. The red soil seemed sandy, crumbly. Jamie could hear the electric motors that drove each individual wheel whining, struggling.

Vosnesensky slowed the vehicle to a crawl. Looking out ahead, Jamie could see only the approaching top of the ridge and the pink sky beyond it. Not a cloud in that sky, it was as clear and empty as the deep blue skies he had known in New Mexico.

"Can’t we go any faster?" Jamie urged. "The moisture’ll be all baked out of the air by the time we reach…"

Abruptly Vosnesensky tramped on the brakes. Jamie lurched forward, reflexively jabbing his hands out to the control panel. He started to complain, then gaped at what lay outside the plastiglass canopy.

"We are here," Vosnesensky said.

What Jamie had thought was the ridge line was actually the rim of the canyon. Beyond it there was a huge, vast, yawning emptiness. They were perched on the edge of a cliff that dropped away precipitously for miles and miles. Another few feet and the rover would have pitched over the rimrock and plunged down forever.

"Jesus Christ," Jamie breathed.

Vosnesensky grunted.

Jamie stood up in his chair, peering as far as he could into the depths of the enormity of Tithonium Chasma. It was dizzying, and knowing that this gigantic cleft was merely one arm of Valles Marineris, that the valley system stretched more than three thousand kilometers eastward, made his head swim even more.

Then he felt his heart clutch in his chest. "Mikhail — it’s there. The mist…"

Frail gray feathers of clouds were wafting through the vast canyon far below, like a ghostly river that glided silently past their round staring eyes.

"The sunlight has not reached that deep into the canyon," Vosnesensky said.

"Yeah." Jamie pushed out of his seat and started back toward the airlock and the hard suits. "Come on, we’ve got to get this on tape before the clouds evaporate. There’s moisture down there, Mikhail! Water!"

"Ice particles," the Russian said. He followed Jamie toward the suit locker.

"They melt into liquid water."

"And evaporate."

"And form again the next night." Jamie was struggling into the lower half of his suit. "The moisture doesn’t go away. It stays in the valley — for a while, at least."

He had never put on a hard suit so quickly. After the lower half, the boots (it was much easier that way), then the torso, finally the helmet. Vosnesensky helped him into his backpack and checked all the seals and connections while Jamie quivered like a bird dog on the scent.

As he was grabbing for the video camera Vosnesensky said sternly, "Gloves! Think before you step outside. Go down the checklist no matter how excited you are."

"Thanks," Jamie said, feeling sheepish.

"In fact," Vosnesensky said, sliding his helmet over his head and fastening the neck seal, "the more excited you are the more you must force yourself to stop and go through the checklist point by point."

"You’re right," Jamie said impatiently.

The Russian grinned at him, like a squat bear showing its teeth. "If you kill yourself here I will be in big trouble with Dr. Li and the controllers in Kaliningrad."

Jamie found himself grinning back. "I wouldn’t want to get you in trouble, Mikhail."

"Good. Now we are ready to go outside."

It was not fair to call it a canyon. Jamie could not see the other side, it was beyond the horizon. The abyss named Tithonium Chasma was so vast, so awesome, that at first Jamie merely stared out from behind his tinted visor, numb with excitement and an overpowering feeling of reverence.

Unbidden, words from his long-forgotten childhood formed in his mind:

"The camera." He heard Vosnesensky’s voice in his helmet earphones. "The sunlight is beginning to evaporate the mist."

Jamie shook himself inside the hard suit and got to work. He panned the vidcam up and down the valley, then from the lip of the rimrock where they stood out to the mist-shrouded horizon. Wherever the sun touched the clouds dissipated, dissolved into thin air. Like the old myths of ghosts that vanish when the sun comes up, Jamie told himself.

"It’s not right to call this a valley," he muttered as he worked the camera. "That’s like calling the Pacific Ocean a pond."

Vosnesensky said, "If you will be all right here for a while, I will set up a sensor unit."

"I’ll be okay," Jamie said. "I’ll be fine."

For hours he watched the mists dissolving as the pale sun rose higher in the rose-pink sky. Down in the deepest recesses of the rocks there must be places where the mist clings, where the sunlight can’t reach, Jamie said to himself. Little oases where there are droplets of liquid water and warmth from the sun’s heating of the rocks. Little pockets down there where life might hang on.

By noontime he had used up three videocassettes and was inserting a fourth one into the camera. The mists were almost entirely gone now and he could see the rock formations standing like proud ancient battlements, marching off in both directions from the spot where he stood. The valley floor was so far below that he could only see the distant part of it, curving off past the horizon. Misty shadows still clung among the rocks down there.

"They’re differentiated, Mikhail," Jamie said into his helmet microphone. "The rock walls here are layered. There was an ocean here once, or maybe an enormous river. Look at the layers."

Vosnesensky, standing beside him once more, said, "All the rocks look red."

Jamie laughed. "And on Earth all the trees look green. But there are different shades, Mikhail."

He pointed with a gloved hand along the line of cliffs. "Look out there. See, this top layer is cracked vertically, weathered pretty badly. But the layer under it is smoother, and much darker in color."

"Ah, yes," said Vosnesensky. "Now I see."

"And the layer under that is streaked with yellowish intrusions.

Maybe bauxite, or something like it. This region must have been a lot warmer once, a long time ago."

"You think so? Why?"