Charles Sheffield - Proteus in the Underworld

Then the colonists and their machines had gone deeper yet, to explore the natural caverns that riddled equatorial Mars. The pockets had been discovered during the first seismic survey, early in the twenty-first century. The results of that analysis had been greeted with skepticism. Some of the caverns showed on the instruments as ten kilometers across and three hundred meters high. The tunneling colonists confirmed those readings, and learned that the cathedral heights were sustained by pillars and buttresses of igneous rock. They set their excavation machines to work, connecting the caverns by a system of branching tunnels far below the stark and frozen surface. The result was Old Mars, where everyone lived. It nowhere came closer to the surface than one kilometer, and in places the Underworld ranged as deep as seven. But no matter the depth, the populated caverns and burrows never strayed more than one degree-sixty kilometers-north or south of the Martian equator.

And few people saw any reason at all to wander the surface, which called for simple suits but elaborate precautions.

Cold. Arid. Airless. Everything up there was better done by smart machines, comfortable under the steady stars in an atmosphere that was still no more than one-fiftieth of the density of Earths, and lower yet in oxygen and water vapor. Even the tourists, interested mainly in sight-seeing, confined their attention to the vast grottoes, natural and excavated, of the deep interior. Sunlight was piped in, conducted along lossless fiber optic bundles to emerge as new miniature suns in cavern ceilings. “Rain” emerged from those ceilings at carefully planned (but seemingly random) intervals. The grottoes had become lush and magnificent, reduced-gravity jungles more riotous than any found on Earth.

With all of this, who needed—or wanted—the surface?

Not Trudy Melford, if Maria Sun could be believed. Melford Castle had been re-located to the Mars Underworld, three or more kilometers down. But now Bey learned that this was not the case. The castle sat only one kilometer deep, as close to the surface as anyone was likely to go. It was also in the extreme north by Martian settlement standards, situated in a previously-empty natural grotto almost seventy kilometers from the equator. The link entry point sat much deeper, ten kilometers closer to the equator.

The castle’s location offered another couple of small mysteries for Bey to ponder. If Trudy Melford wanted to explore new forms in the Mars Underworld, why not choose a deep location close to them? She surely had enough money to put her home anywhere that she wished. But she had picked a bleak spot that was by Martian standards far from the comforts and company of civilization, and farther yet from the Underworld. She must have been forced to install her own air compressors and light pipelines, and then grow the vegetation to make the Melford grotto hospitable rather than merely habitable. The committee that controlled the living space of Old Mars should be paying Trudy, rather than the other way round.

The car they were in followed its own programmed route. Their course wound its way through a maze of well-ht tunnels and broad highways. Bey felt the decrease in air pressure and knew that they were steadily ascending. He saw a handful of other cars and occasional cargo barges, but no settlements. They did not pass through any large grotto or agricultural cavern. Apparently Trudy controlled a private road between Melford Castle and her link entry point.

After her first warm greeting she had not spoken to him. She surely knew that he had not been to Mars for a long time, and understood that he needed time to adjust to the changes. But with the car’s snug seating it was impossible to avoid more physical forms of contact. Bey was aware of her hip and warm shoulder, touching his. Her dark hair gave off a faint scent of roses. Jarvis Dommer, up in front, looked straight ahead and was mercifully silent—the result, Bey suspected, of direct orders from Trudy. If she was the Empress of BEC back on Earth, how much more was that the case here on Mars, where the controls on her actions were fewer?

For the past couple of minutes the tunnel had been steadily widening, changing from a two-lane highway to a broad plain of dark rock forty or fifty meters across. A row of floor lights now marked the car’s path. The walls and roof of the chamber were far-off and no longer visible.

Then the road illumination ended. The car’s lights also dimmed and faded to nothing. Bey was suddenly in limbo. The car’s motor was inaudible, but he had the feeling that their forward motion was slowing. He felt a hand on his, and heard Trudy’s soft voice in the darkness beside him, “Melford Castle, Bey Wolf. Welcome. I hope that you will choose to remain here for much longer than one day.”

It had been carefully staged, of course—whether for him alone, he could not tell. A diffuse light appeared, high and far-off. At first it was like the glow of an Earth sunset, soft- edged and tinged with red. As the car moved steadily forward the light strengthened and changed, to become the white blaze of Mars noon. Bey knew that it was exactly that—piped light, carried in to form a new sun in a cavern roof high above them.

Still there was no sense of scale. That came only when they had moved another half kilometer and Bey could see what lay ahead. Melford Castle had been transported from the Yucatan peninsula stone-for-stone. Walls of white limestone glimmered now in front of him, shining in a light bluer than they had ever seen on Earth. The atmosphere of Mars was thickening—slowly—but the short wavelengths of the solar spectrum still came through here far more strongly than they had ever been seen in Castle Melford’s original setting.

Bey had never visited the castle, but he had heard of the eccentric tastes of Ergan Melford, founder of BEC and amateur architect. The topmost blue-and-gold octagonal spire of the fourteen-story, hundred-and-fifty room mansion stretched ninety meters above the castle’s foundation. The light source in the roof of the Melford cavern shone high above that.

Bey looked, measured with his eye, and decided that he was in an open space maybe two hundred meters high and two and a half kilometers across. The transformation of the grotto had begun, but obviously it had far to go. Thin lines of greenery petered out a few hundred meters from the castle walls. Beyond them hundreds of machines were at work converting bedrock to fertile soil by seeding it with bespoke bacteria and algae. For at least another few years, oxygenated air must be brought into the cavern—at a price—from supply points deeper in Old Mars.

The car was easing its way silently forward, on a road that in its final hundred meters was bordered by sweet-smelling bushes. It led straight to an arched entrance to the castle itself. And there, in an English-style interior courtyard of cobblestone floor and red brick walls, the car stopped. Jarvis Dommer at once jumped out and disappeared through a wooden door that led inside the ground floor of the building.

Trudy climbed out more slowly and turned to Bey. “Are you tired or hungry?”

He realized that it was only the third time that she had spoken to him since his arrival on Mars. He had to pause and think about the answer to her question. With so many time zone shifts he had little idea what his own biological clock was doing. But improbable as it seemed, less than three hours ago he had been sitting in his living-room on Wolf Island, eating breakfast and staring out at the calm waters of the Indian Ocean.

“Not tired. Or hungry. Suffering from sensory overload, maybe.”

“Do you want to rest?”

“That’s not why I came to Mars.”

“Good. Dommer will find a couple of suits.” She saw his expression. “Don’t worry, they’re not for you and him. They are for you and me.”