Diamond Mask (Galactic Milieu Trilogy) (64 page)

Jack joined Rogi and donned a jacket. When the big Ford four-wheeler pulled up he opened the starship’s air lock. The waiting vehicle had cleated tires nearly a meter in diameter and stood in mud up to the hubs. Jack propelled Rogi and the carrier with the CE equipment into the front seat with unceremonious PK, levitated himself into the backseat, and slammed the truck doors after them.

“Welcome to bonnie Caledonia,” said Dorothea Macdonald, lifting her hand in the open-palmed operant greeting. “Sorry about the wee sprinkle. It’ll pass by in half an hour or so.” She introduced IG Sorley, a well-built man in his late thirties. Both of them wore Day-Glo orange environmental suits without headpieces. Their hair was soaked and their faces beaded with raindrops.

The Bronco began to wallow toward the lighted buildings. “Thank you for coming, Jack,” the Dirigent said, rather coolly.
“Uncle Rogi should never have pressured you to involve yourself, but—”

“He didn’t. I’m glad to be here and I’ll do anything in my power to help. I can’t understand why you didn’t ask me yourself.”

She was staring straight ahead, clutching the steering wheel in a white-knuckled grip. “I wouldn’t have presumed. You have so many other demands on your valuable time. I asked Rogi to approach your brother Marc about lending us the new CE equipment from CEREM, but I never dreamed he’d ask you to come here.”

“Oh, for God’s sake,” Jack muttered. “Would you really put Caledonia at risk just because you can’t stand me?”

“I have the greatest respect for you. I simply didn’t feel it was proper to involve you in a hopeless situation.”

“How do you know it’s hopeless?” he challenged her.

“You can see for yourself in just a few minutes. Our chief surveyor is ready to give you an overview. I told you in our subspace conversation yesterday that you were only wasting your time—”

“Dammit, let me be the judge of that!”

“I’m responsible for this world, not you, Jack!” she snapped. “And the final judgment on this project will be mine!”

“Then be sure that judgment is based on reason and not on your stubborn pride!”

“Will you two cut it out?” Rogi pleaded.

“One piece of good news,” Calum Sorley put in hastily. “Another geozap recruit signed on. From Okanagon. She’ll be here by suppertime.”

“That’s eight qualified CE operators all told, then,” Jack muttered. “Better, but still not enough for the fifteen-head metaconcert the job probably needs.”

“The Yakutia operator made a suggestion this morning,” Sorley went on. “She said that we might abandon the metaconcert approach and attack the subcratonic reservoir with multiple individual creative impulses instead. It seems they’ve had some success with the technique on their world, coping with smaller magma chambers. The beastie under Clyde is much larger and deeper, of course, but with the added power of your E18s …”

“I’ll need a better picture of the reservoir,” Jack said.

“We’ll give you a full Tri-D model with all the bells and whistles right now—unless you’d rather freshen up first.”

“Not at all. Let’s go for it.”

Sorley nodded. “Narendra has it all set up.”

They were approaching a large portable building crowned with antenna arrays. The Dirigent skidded to a stop in front of it, flinging a sheet of muddy spray. The four of them climbed out and raced through the rain to the entrance, where they were met by a dark-complected man with a dazzling smile. The Dirigent introduced Caledonia’s chief surveyor, Narendra Shah MacNabb. He greeted Jack and Rogi with effusive enthusiasm and led the way to a holographic display chamber.

“Are you familiar with the latest geophysical graphic models?” the scientist inquired. “No? Well, you should find this interesting. I’ll just start the simulation.” He glanced at a little monitor just outside the chamber, took a portable keypad from its holder, and tapped away for a few moments. Then he opened the door.

To a three-dimensional vision of hell.

“Christ de tabernacle!” Rogi gasped, backpedaling in dismay.

But the surveyor only laughed, beckoned for them to follow him inside, and shut the door. The holographic representation of the tectonic environment beneath Caledonia’s crust filled the entire room, so that an observer seemed at first to be immersed in flaming chaos. Only gradually did the scene take on a sense of order and even stark beauty, with semitransparent streams of fiery scarlet, vermilion, and yellow forming dynamic three-dimensional patterns that one could examine at close range, from any angle.

At the other end of the room a platform with shallow steps running along its entire length was barely visible through the simulation. Narendra Shah MacNabb led his guests through the midst of the conflagration and up onto the platform, where it seemed as though their heads broke through the illusion’s surface and into open air. They became giants, looking at the southern shore of Clyde landmass and the adjacent sea. Then, as they moved down one shallow step at a time, they effectively descended beneath the lithospheric crust and into the depths of the planet. Clyde grew a massive root, solid in the top 30 kilometers or so and stiffly molten to a depth of about 160 kilometers. The entire continental lithosphere was embedded in the much thinner oceanic lithosphere that formed the floor of the sea.

“The fiery, moving portion of the model below the lithosphere,” MacNabb said, “represents an upper part of the planetary mantle called the asthenosphere. It behaves more like a
liquid than the more rigid lithospheric mantle that generally stays coupled to the continent. The swirling areas in our model asthenosphere are convection currents—greatly accelerated in the simulation, of course. Note that they’re very complex. The individual convection cells change shape and also exhibit changing velocity in response to heating and cooling and alterations in the density of the circulating material. Now let’s move down the rest of the steps and inspect the asthenosphere immediately underneath Clyde. Very soon now, the simulation is going to demonstrate the catastrophe scenario.”

They took up a position just “south” of the continent, where they were able to look up through the semitransparent root.

“The umber-colored area with the deep crimson lower portion represents the Clyde craton and its associated lithospheric mantle. We’re right on top of it here at Windlestrow Muir. The craton is the southerly, most ancient part of the continent, which was presumably formed when Caledonia first solidified some three billion years ago. The lighter-colored continental regions around the edges and to the north are younger rocks that accreted to the craton throughout the aeons as the landmass slowly grew.”

“Largish craton,” Jack observed.

“Callie’s continents have grown much more slowly than those of more Earthlike worlds,” said MacNabb. “But never mind the reasons for that. Look lower now, into the asthenosphere right in front of us. Notice how that very large convection cell beneath Clyde is losing stability—actually fissioning while we watch! (Of course the event actually took place over a period of several million orbits.) Now look down here. Ascending amidst the turbulent area is an elongated thermal anomaly that looks a bit like an inverted fiery raindrop. It’s less dense and much hotter than the surrounding area of mantle.”

“A plume!” Rogi exclaimed.

“No, a diapir,” Dorothea Macdonald said. “A rising blob, not a persistent upwelling stream.”

“Exactly,” the surveyor agreed. “We’ve speculated that the diapir resulted from the remobilization of very ancient, so-called ‘fertile’ mantle material that never previously surfaced and outgassed. Whatever its origin, it contains a high percentage of volatile material—mainly carbon dioxide and water. Now watch what happens when it reaches the lower boundary of the lithospheric mantle at the hundred-sixty-klom depth.”

The rising portion of magma, colored a brilliant golden-yellow
in the simulation, reached the stiff mantle of the cratonic root and halted, spreading out and partially penetrating the crimson. After a moment the ascending diapir pinched off from below and its matter formed a reservoir at the deepest part of Clyde’s lithospheric mantle.

“At this point,” Narendra Shah MacNabb said, tapping his portable keypad, “I’ll speed up the simulation. In actuality, the high-pressure reservoir of volatile magma remained lurking in place for an unknown length of time.”

“Just peacefully cooking up diamonds,” the Dirigent said, “as carbon-laden diapirs are accustomed to do.”

The surveyor nodded. “It stayed relatively dormant until natural changes in the ordinarily stiff and resistant lithospheric mantle allowed it to resume its ascent.”

In the simulation, a tiny thread of magma began to travel upward from the reservoir’s top.

“That ascending queue seems to have begun to move only about ten years ago. What we are about to see now is an extrapolation that will be valid if no CE modification is accomplished … That is, if human intervention proves impossible.”

The crimson part of the cratonic root swirled in minute turbulence. Instantly the thin filament of golden magma enlarged and pushed upward at an accelerating velocity. It smote the underside of the umber cratonic crust, broke it, and burst forth at the surface. In moments, the reservoir contents were drained. The observers stood silent for a moment, and then the Tri-D simulation winked out, leaving them standing in a featureless empty room.

Rogi spoke hesitantly. “What happens on top when the thing blows? Aside from a shower of diamonds, that is.”

“Imagine,” MacNabb said gently, “the eruption of fifty Krakatau volcanoes—but because of the adiabatic decompression of volatiles in the magma, the eruption would be cold, not hot. What we call a diatreme.”

“There would be stupendous earth tremors,” Dorothea Macdonald said. “Clyde itself would be devastated, of course, but that’s not the worst of it. Airborne ash, carbon dioxide, and vapor would pollute Caledonia’s atmosphere and render it nearly opaque to sunlight for an indefinite period. A Great Die-Off would very likely ensue. The planet would have to be abandoned.”

The surveyor opened the holographic chamber door and held it politely. “I hope the brief simulation has been of use to you,
Director Remillard,” he said to Jack. “Detailed information on the volatile-magma reservoir is available in the survey data bank, and of course I myself will be entirely at your disposal if you should decide to attempt a modification.”

Jack hesitated, reluctant to ask the obvious question. He had no doubt that Dorothea Macdonald already knew the answer. “I wonder if I might I ask you for a snap opinion, Dr. MacNabb—quick and dirty.”

The chief surveyor gave a small shrug.

Jack took the E18 carrier from Rogi and hefted it casually. “I know you’re familiar with the conventional type of CE geozap modification. We now have eight grandmaster operators available, and I’ve brought experimental CE equipment that will boost their metapsychic output by a factor of three hundred—as opposed to the older-style helmets that augmented a hundred times. You know the volume of the reservoir and its constituents. In your opinion, will we have enough creative energy available from unconcerted joint output to bleed off the volatiles and sink the magmatic residue back into the asthenosphere?”

Narendra Shah MacNabb knit his brow in a courteous imitation of earnest thought. Finally he looked Jack straight in the eye and said, “Not a prayer.”

The Dirigent of Caledonia, looking very small in a bulky white sweater and a pair of tartan trews, was a little late for supper. She and the newly arrived CE operator from Okanagon, a slender black woman named Tisha Abaka, came to the table in the scientists’ mess where two chairs had been saved for them. They plumped down after minimal vocal greetings to Jack, Rogi, and the CE operators and fell like wolves upon the roast lamb with rosemary-anchovy sauce, bashed neeps, and butter-drenched baked potatoes. Everyone else seemed equally hungry and the conversation was entirely telepathic.