THEY TOOK up the 39-degree course, heading directly for Dane’s co-ordinates. It was 0135, an hour and thirty-five minutes after midnight. They had less than twelve hours.
According to the last fix, they were a thousand yards into the lichens. Little more than half a mile. It was at least three miles more to the estimated location of the missing party. A mile an hour was now as much as they could expect to make through the lichen forest. Just to walk to the plotted location and return far enough to get out of the lichens would approach seven hours, with no delays. If the terrain got no worse. Sunrise being due at 0614, that made them emerge at least two hours after daylight. That was the best, any way Dane figured it.
They came into open ground, in areas forty to fifty yards across with the familiar red soil showing up in their lights After a time a sensible downhill grade developed, but the lichens were again thicker and their speed did not improve. The haze now obscured the few stars of early night, and the beacon of the spacecraft had dipped below the crest of the descent.
Wertz said, “One thing about your theory doesn’t jibe. I went along with you on your plot of the spark-fire concentrations. It made as good sense as anything that they had something to do with Pembroke’s party. But if you’re right about that, how come no concentrations where we found Houck’s body?”
“It doesn’t fit,” Dane admitted. “But if the concentrations signified anything at all about Dr. Pembroke’s locations, then they proved that he moved three thousand yards farther into the lichens from one night to the next. That’s what we’re counting on.”
McDonald said, “It would have helped if we could plot them in the daytime.”
“A lot of things would help,” Wertz said. “If we only knew about them.”
Between 0130 and 0230 they made less than a mile. To maintain familiar hour relations with sun-time, their Earth watches had been synchronized at every midnight, moved back 37 minutes to accommodate the 24-hour-and-37-minute rotation of Mars. At 0255 hours by their improvised Mars time Dane estimated that they were near the place of concentration recorded for Dr. Pembroke’s first night in the lichens.
He called McDonald. “How about getting us a fix?”
They were practically on it. Sixty yards short. Some to the right. They were steadily veering to the right hand.
After they had swept the location for twenty minutes, they resumed course.
Another forty minutes, at 0425 hours, and they came on a bare depression running ribbon-like and fifty yards wide diagonally across their path. It looked like an old Earth gully rounded and filled in with wind-blown red soil. It extended to left and to right as far as their lights would shine.
“Rope me,” McDonald said. “I’m going into it.”
He edged down the sloping bank and kicked at the loose dust. It was ten or twelve inches deep at the bottom, but he thought the footing underneath was the same clay-like stuff that had been found under the red plain.
They made their 0430 call and reported the find. The fix showed 5370 yards in and slightly left of course. They had overcorrected.
Dane said, “Anybody coming through three miles of nothing but lichen beds would be sure to explore this. It’s the first different thing they would have seen.”
“So we follow it,” Wertz said. “It’s slanting ahead pretty close to our way.”
The going was slower. It was like walking in drifted snow, only the dust did not help them by packing. The minutes perversely increased their tempo.
McDonald thrust out an arm. “Something’s on the ground.”
It could have been spread out for a sign. The shoulder strap was unbuckled. One end of the strap stretched straight forward, pointing along the channel. The other lay at right angles, indicating the bank toward the spacecraft.
“It’s a specimen bag,” Wertz said unnecessarily.
Dane said, “Now we know we’re on the trail.”
Wertz said, “Maybe Houck was coming back for help and put it down for a marker.”
“We ought to see some tracks,” McDonald objected. He pointed to their own passage.
“Not necessarily,” Dane told him. “We had a five-mile wind early this afternoon. That’s plenty to drift light dust.”
They waded on. After another half hour the dust channel bent to the left in a sharp curve.
“It’s taking us back toward the 39-degree course line now,” McDonald said.
The steady shuffle took them along more red channel and between more lichen-covered banks. It could be no dried-up watercourse, not on Mars, but they could not imagine a cause for it or advance any reason for the failure of the lichens to spread over it. With only minor alteration in course it was more like a wide, dusty sunken road than anything else. But who would have made a road?
“Maybe ages ago. Hundreds of thousands of years,” McDonald said.
“It’s pretty well agreed now that Mars is a young planet, as far as life is concerned,” Dane told him. “The lichens are probably at the beginning of life here. Not the end. Between the two planets, Earth life is the old life. Besides, the lichens would have covered over a road long ago.”
“It’s probably a surface fault of some kind,” Wertz said. “A fault could have exposed some mineral substance the lichens don’t like. I’ll take some samples on the way back.”
“It’s time for the 0530 report,” McDonald said. “Maybe we ought to hold it up a few minutes. We’re almost to your location.”
“Better get a fix,” Dane said.
“We’re going to have to make speed out of here,” Wertz said. “It’s 0530. We left the spacecraft at 2120. That means we’ve been eight hours and ten minutes getting here. Eight hours and ten minutes from now is 1340 hours, and Colonel Cragg said he takes off at 1300 regardless.”
“We can get back a lot faster,” Dane said. “We ought to come on to them in another thirty minutes, if they’re where we think they are. That’s 0600. That leaves us seven hours. In a straight line it’s only about eight miles and a half back to the spacecraft. With no time out for searching around on the way back and in the daylight, we ought to make it to the edge of the lichen forest in three hours and a half without any trouble and make it over the dust plain in two and a half hours more. That’s six hours. Well still have an hour for cushion.”
“What do we do if we have to carry them out?”
“We take off their gravity weights, and pack them out. One each. We’ll make it. We’ve got to.”
“We can put them in the specimen cart when we get them out of the lichens,” McDonald said.
The fix was 6100 yards in and 150 yards right of course. About 428 straight-line yards to go. Course 18 to 19 degrees.
According to the compass-sighting, the channel ran at 21 degrees, shy. “Let’s follow it.” Dane said. “Pace it off. Maybe they planted another marker where they left it.”
It was almost time for the brief dawn that the attenuated atmosphere afforded the planet. For the first time Dane felt real fatigue as he realized that the sun would soon be daylight around them and over the weary miles back to the spacecraft. He slogged along. Successful or unsuccessful, it would be a long hard pull.
At the far edge of his light, he vaguely saw something. A bulk in the channel ahead.
“Hold it!” he sang out. “There’s something up there.”
They huddled, striving to pass the fuzzy limit of vision. There was something. Something that was not naked, ocher-colored dust.
“Dr. Pembroke!” Dane called. “Dr. Pembroke. John Dane calling. Can you hear me? Can you see our lights?”
He strained for acuity below the faint hum of the ear-phones, but there was only the silence of the Martian night. Nothing moved.
“It’s not big enough to be a man,” McDonald said.
“Anyway, why doesn’t it move?” Wertz said. “Our lights are plain to see.”
“This is my play,” McDonald decided. “I’ll go have a look.”
Dane said, “This safari was my idea. Whatever is out there has something to do with Dr. Pembroke. I intend to go see. Get in contact with the spacecraft and wait for me here. We don’t know what it might be.”
Wertz said, “Why don’t we all go? Three are better than one.”
Dane felt the thing brush his scalp. He had not yet put it in words. Not even to himself. Now he had to. “You’re going to think I’m off my zip, but tonight, while I was plotting the spark fires, something made me think and I can’t forget it. Colonel Cragg would have laughed me out of his office if I had even mentioned it. But this is it. For a minute I began to think maybe there’s intelligence on Mars besides our own. I couldn’t help it. You have only to look at the chart I made to see it for yourself. Some something could actually be directing the patterns of the spark fires. Something very probably hostile.”
Their silence was heavy.
“I’m not cracking up. I just think you ought to know what I believe is very possible and you ought to be prepared to relay it to Colonel Cragg. If by any chance I could be right, whatever it is may have destroyed Dr. Pembroke, and it could very well be aware of our presence here now.”
Wertz swore. “You pick a hell of a time to bring up an idea like that! You want to give me the shouting creeps? You know there’s no life on this planet except this damn vegetation. How could there be? You going back to that idea about life based on something else than carbon? Like the silicon atom?”
“I don’t know,” Dane told him. “I haven’t any idea. Call it a hunch, if you like.”
“You bet I will,” Wertz snapped. “A damn poor one. Unless you believe in ghosts. And ghost mechanics and ghost architecture. Desert ghosts,” he laughed shortly.
“Nevertheless,” Dane went on, “there are patterns to the spark fires that seem to be associated with our presence and with our physical location. Colonel Cragg noticed a new one. That’s why he was hot to move up the take-off. Only what he was really afraid of was a step-up in the penetration rays.”
He saw Wertz turn his helmet ponderously at McDonald. “Kid,” he heard him say, “you’re official. You stay here and report. I don’t take in Dane’s ghost story, but if something does pop up out there, Cragg’ll believe you. He won’t think you’re off your base.”
“Dammit!” Dane said, in spite of himself. “The sun will be up in fifteen minutes. It’s getting lighter in the east now. I’m going ahead. Lieutenant McDonald is technically in command here, I suppose. Let him——”
“I’m coming with you,” McDonald said quietly. “Wertz, I have no real authority over you, but I’d like for you to stay and cover us.”
“With what?” Wertz said bitterly. “A comic-strip ray gun? You want me to shoot lichens with a six-gun? Or maybe Danes ghost men? You get up there, you’ll find exactly nothing.”
But when they went forward, he remained at his post. They heard him calling the spacecraft. “Wertz to Baker Home.”