Echoes of an Alien Sky (36 page)

"Could be," Yorim agreed.

"Now look at this," Casselo said. He activated another screen to show the map of the Californian Gulf that Kyal and Yorim had introduced that morning. The pilot's notes appeared in an inset. Casselo recited them as he entered commands to add the details in sequence. "Eleven o'clock approach." A red line appeared to one side of the map, oriented at the same inclination as the lie of the Gulf. "Midway between La Paz . . ." A circle appeared, showing where the town had once stood on the eastern side near the tip of the peninsula, "and the coast." He moved the line horizontally across until it was centered in the position indicated. The Gulf narrowed toward the north. About halfway up, the coastline closing from the east fell more-or-less into alignment with the red vector.

"Following the right-hand shore," Chown, who was among those present from yesterday, read from the notes in the inset box.

"Yes," Casselo confirmed. "But now watch this. Here's the pyramid at Camp 27." A triangular icon appeared. The red line slanting upward at eleven o'clock from the midpoint of the Gulf's mouth passed right over it. "Coincidence?" Casselo asked. Murmurs of interest came from all sides.

Yorim turned to Kyal with an astounded expression. They had probably seen the implication before most of those present. It meant that the Camp 27 pyramid probably hadn't been some kind of prototype at all. The facts were more likely the other way around: The construction on
Luna
had been the prototype, to develop the technology before building the final version down on Earth.

Casselo read the expressions on their faces. "Does it mean what I think it means?" he asked. The voices subsided as one by one the others realized there was more to this than everyone appreciated. "Care to spell it out for us, Kyal?" Casselo invited.

"A discharge attractor right on the flight path." Kyal glanced questioningly at Yorim. Yorim nodded. Kyal explained, "It wasn't a simulator program to help local supply pilots find Providence. It was for training the crew who would bring everyone back. That's the descent path for a returning spacecraft."

"Which helps explain what it was doing at Triagon," Casselo said, nodding.

"The wording starts to make more sense that way," Yorim said, reading the screen again. "Nobody could have known who would be piloting the craft when it was time to come back. It would probably be somebody who had never been there. You wouldn't use place names or arbitrary conventions that might change. You'd base the directions on things that would be more permanent, like cardinal directions, major terrain features.. . ."

"La Paz is a place name," Chown pointed out.

"Yes, but it also says 'Testing,'" Kyal said. "I think Yorim could be right. If this is from when they were still developing the program, it could just be a bit of loose terminology by somebody involved in trying it out."

Chown mulled, then rocked his head from side to side. "Mm, well, okay, maybe."

"'Homing peak bearing' seems clearer now," Hiok, the planetary physicist said as he read over the text. "It says it checks as a directional pointer. What does 5.778 mean?"

"The Terrans used a three-hundred-sixty-division circle," Chown murmured, half to himself. Venusians did too, as it so happened. The number offered such a convenient choice of divisors as to make it an obvious circular measure.

"To four significant figures?" Casselo queried dubiously.

"Can we be sure it means degrees?" Acilla Jyt asked. A short silence fell. Hiok pulled a sheet of paper from a pile on the work top by where he was standing and leaned over it to begin scribbling something.

Finally, Yorim said thoughtfully, "A more universal circular measure would be radians—independent of anyone's system of units."

"That's a possibility," someone agreed.

"What are they?" Acilla Jyt asked.

"Two pi of them make a circle," Yorim said. "Engineer's unit. More convenient for lots of things. Fifty seven point three degrees."

"Oh."

Casselo took out his phone and flipped it to compute mode. "Five point seven, seven eight. . . . Fifty-seven point three. . . . " He recited. "It works out at three hundred thirty-one degrees. Where would they start from? North, rotating to the right?"

"Try it," Yorim said.

Hiok did the subtraction mentally. "That would put you twenty-nine degrees west of north." Even as he said it, Casselo added a blue vector to the screen, starting from the same center point at the bottom of the Gulf and angling up at twenty-nine degrees west of north. The divergence from the red line already there was barely discernible. Murmurs of astonishment came from around the group, with a low whistle from somebody.

"What do we have along it?" Chown asked.

Casselo composed an input to access the survey files of physical terrain data and display the major peaks. Although the chain running to the west of the flight line, called the Sierras, contained many, the line, surprisingly missed all of them. The eyes gathered around the screen searched up and down its length in bafflement. Then Kyal said, "Up there, right at the top." He had to step forward and point. At the very top of the map, right on Casselo's line just before it ran off the edge, an isolated peak stood out conspicuously from the relatively flat surrounding terrain. The Terran name for it was Shasta.

Hiok blinked. "But that's got to be, what? . . ." He checked the scale. "It's something like thirteen hundred miles north from the mouth of the Gulf."

"Nowhere near Santa Cruz," Chown said.

Yorim came in. "It doesn't have to be if it's just a directional beacon." He thought for a second longer. "In fact, it could strengthen the case for this not being something they put together for local supply pilots. I agree, you'd never see it from an aircraft anywhere around Santa Cruz. But from long distance at the altitude of an incoming spacecraft, it would be an ideal marker. Short of a radio beacon, you couldn't ask for anything better." Silence from all round greeted his words.

"There's your homing peak," Casselo said.

A number of lakes lay along the path, along with the sites of others identified as having dried up. None stood out as being of any great significance. Of course, there was also the possibility that more had vanished without trace.

As to the two "Markers" that the notes referred to, the general feeling was that these were probably peaks too, marking progress along the descent path. But until the numbers associated with them could be interpreted, little more could be said. Almost certainly they denoted distances, but there was no indication of the units they were expressed in. Unlike the case with circular measure, there was no common standard that immediately suggested itself.

Acilla checked in dictionaries of Terran terms and discovered that "GZ" stood for Ground Zero. Almost certainly, it meant the location of Providence itself. It seemed unlikely that any prominent terrain feature would be associated with a survival cache that was intended to be kept secret. But it was somewhere along that line. If they could only make sense of the distances, they would have it.

The next day, Casselo and Kyal discussed the findings with Sherven. Sherven contacted the scientific director of the Western North America Regional Base and requested a low-altitude aerial survey to be carried out along a fifty-mile-wide corridor centered on a line running twenty-nine degree west of north from the eastern edge of the California Gulf, to where it intersected the coastline far to the north.

The first significant result came in a couple of days later: another partly buried pyramid. It was right on the approach path near a place that had been called Yuma, on the Colorado River. From descriptions and pictures sent through by a hastily despatched ground team, Kyal identified it tentatively as a secondary, backup attractor, a little under two hundred miles downrange from the one at Camp 27. The dimensions and general scale of the setup suggested an incoming craft that was extremely large, arriving from a great distance, or both. This didn't sound like something making the relatively short hop back from Luna. So maybe there had been somewhere else in the Solar System that had changed beyond recognition since the time of the Terrans after all.

Earth!

It was a sight that Zaam had thought he would never see. The legendary ancestral home of the tiny residue of humanity that he had shepherded back after the long exile of their kind. Its form was familiar from images preserved and handed down through generations, but now it was really out there ahead of the ship, shining blue and white against the background of stars—as if it had been waiting.

The attempt to live away from Earth had failed. Contact was lost. Most of the plants, the animals, and the children died. For a hundred or more generations—nobody knew for sure—the colony clung on the verge of extinction, unable to muster the will or the strength to rebuild the facilities necessary for refurbishing the still-orbiting mother ship to make a bid to return. Finally, Zaam's father was born, and he had organized the manufacturing and re-equipping. Tears of joy and final release from the years of strain tickled down the old man's cheeks. The promise that he had inherited was fulfilled. He had brought them home.

As the ship drew closer, the swirls and streaks of color resolved into recognizable parts of continents outlined between the clouds. The long, two-part American hemisphere, although changed a little in places was easily identified, extending almost from pole to pole. West of it stretched the vast ocean occupying almost half the planetary globe. A flyby followed by long turn into an eccentric closing orbit to shed velocity brought the farther hemisphere into view, with its vast northern landmass and stubby southern-pointing extension on the western side. After the caustic wilderness in which the generations had struggled and died, the bands of warmth and color adorning the disk from its green equatorial band to the brilliant ice caps spoke of life and vibrancy that none of the ship's occupants had ever in their lifetimes been capable of imagining.

Despite objections from the others, Zaam insisted on going down to the surface with the advance party. He would let nothing deny him this moment. The lander detached from the mother ship and went into an almost polar descent orbit, coming in over the southern ice cap on a north-bound trajectory skimming the tip of the southern American continent to the right. The computer projection showed their course coming into alignment with the long, narrow gulf far to the north on the western coast, still hidden from direct view by the planet's curvature. "Disengage descent program," Xoll, the commander on the bridge deck ordered.

"Auto unlocked. Approach vector confirmed," the Flight Officer responded.

It was up to Wirton now, tense and concentrating on his displays at the manual piloting station. He was the best, and had trained assiduously on the simulator for this task. It had to be right first time. After shedding its share of the excess charge accumulated through the voyage, the lander would not have the reserves to regain orbit for another attempt. The others around the bridge watched and waited in a silence broken only by the hum of power coursing through the structure and the swishing of air flowing from the ventilator grilles. A display above the pilot's station showed the directions that had been preserved since the time of the ancestors.

The western American coast unrolled slowly ahead and below, the screen images enhanced from long-range infra-red scans. The coastline to starboard receded to become a thin, twisting neck joining the two continents. Ahead, the target gulf crawled into sight over the horizon. A superposed sliding graticule showed Wirton's fine course adjustments bringing their approach over the center point, bearing set on 5.778 radians. Telescopic and infra-red revealed a high mountain peak dead ahead at the limit of visibility, standing white above surrounding plains. It had to be the homing target!

The mouth of the gulf rose up and opened out ahead. . . .

. . . stretching away like a blue carpet. The image inside Kyal's all-round vision helmet was coming from the aerial drone that he was remote-piloting from
Explorer 6
, making a test approach up the center of the Gulf of California. Altitude twenty miles, descending, bearing set at twenty-nine degrees west of north. The coastline closed slowly inward below from the right until it was immediately below, like a finger pointing the way. Beyond the head of the gulf, the cloud-speckled, red-brown landscape disappeared into haze. He intensified the image enhancement to reveal Shasta standing out dead ahead like a white beacon, radar-echo range currently reading eleven hundred fifty miles.

The Marker distances had made sense instantly when interpreted as fractions of the distance from the mouth of the gulf to Shasta. The purpose of the test run was to identify the Marker peaks from the numbers given, by watching and scanning both sides of the descent path as the drone made its run in.

The Flight Engineer's voice came again. "Charge dump echo signature. Thirty miles, directly ahead."