“Dead people,” said Darvin, in a hollow voice. “Come on.”
A path on the floor of the cave had been worn smooth by the tread of previous visitors. In the electric torchlight, it almost shone. Darvin and Orro paced along it. The occasional droppings of the small flitters apart, the cave was dry, with nothing of the dankness and weed that Darvin had half-expected, from some dim association with sea caves. The air too was fresh; some of the caves were said to connect to sinkholes well behind the cliff-top, and their occupants — human visitors or animal tenants — in danger of being flushed out in the flash floods of rare rainstorms. The risk seemed small.
“I’m told it’s about two eights-of-eights of steps,” said Darvin.
“When did you start counting?”
“Good point,” said Darvin, and began his mental count at a double-eight.
But the sight they had come to see was hard to miss.
The cave widened not quite enough for the space to be called a chamber. High on its walls, and arching over its roof, were eights-of-eights of coloured drawings. The sketched outlines of humans were so crude that they could as well have delineated moths. Animals, prey and grazer, flitter and cursor, were rendered with a colour and tone and line that made one hallucinate that they breathed. Oddly, they were untouched by droppings; only a soot-stain here and there sullied them, from the guttering wooden torches of the first discoverers, scientists — and later, gaping, adventurous travellers — of the Dawn Age.
It was not the only, or the best, example of the cliff-men’s art in Seloh: new caves were being discovered all the time, right along the whole edge of the tableland. But it was famous, and close to wing, and Darvin knew what picture to look for. He scanned the walls with his beam.
“There!” he said, lighting on a patch about two wingspans up the wall.
“That pattern of dots?”
“Yes. It’s generally supposed to represent the Queen and the Daughters — they’re picked out in a green stain made from, I believe, some kind of copper salt. And of course, being ignorant cliff-men, our clumsy ancestors only bothered to pick out a few.”
He turned to Orro. “If you wouldn’t mind, I’d like to stand on your shoulders for a moment.”
Orro shrugged. “If you must.”
Darvin backed off, sprang into the air and flapped. He hovered for a few seconds, then lowered his feet on to Orro’s shoulders. He resisted the reflex to curl his toes. Keeping his wings outstretched for balance, clutching the heavy torch, he peered at the stone wall. The largest of the green markings was a precise circle about the size of the palm of a hand. He’d consulted the two most reputable books on cave paintings, and in the brief passages describing this cave the sharp outline was held as evidence that the patch represented the Queen (as well as, less reliably, that the cliff-men had had sharper eyesight than their modern descendants). Around Her was a seeming random speckle of green dots, each the size of a fingertip. They didn’t look like even the more prominent of the Daughters; it was indeed tempting to regard them as a crude indication.
He looked closer yet, leaning forward then almost toppling back, then forward again as he regained his balance. In among the green spots were others, fainter and smaller but definite. Some were made with ochre, some with what he guessed was sulphur, others perhaps with chalk; all of them ground into the sandstone with such force that the markings had left little pits. Red, yellow and white; there was no mistaking the intent.
“Take your time,” said Orro.
Contrite, Darvin hopped off and alighted on the floor. Orro rubbed his shoulders.
“Your turn,” Darvin said. He stepped forward and took a notebook and pencil from his belt pouch and handed them to Orro. “Hop up on my shoulders and draw what you see. Make a note of the colour of each spot. I’ll shine the torch up for you.”
A minute later Darvin was certain that Orro must be heavier than he was. He clenched his jaws and concentrated on keeping the light steady. After another few painful minutes Orro grunted and jumped off. Darvin felt for a moment light enough to fly, and too sore to do so. Orro returned the pad and pencil. Darvin looked at it in the electric light. It was spread across the opening of two pages, a score of annotated circles and dots.
“Neat,” he said. The electric light was fading and yellowing by the minute. “Let’s look at it outside.”
They squatted in the cave mouth, leaning back on the mesh doorway, facing an abyss of air, a shimmer of grassland, a horizon line of sea. Darvin felt his every muscle and nerve sing with relief.
“I don’t believe the cliff-men lived in caves at all,” he said. “They’re just too horrible.”
“That is a widespread scientific opinion,” said Orro. “They left their dead in them, or perhaps just their illustrious dead; they may have used the places as stores, or as places of worship and meditation; but the popular belief that they inhabited caves is ill-founded.”
“I’m glad to hear it,” said Darvin. He sighed; he was almost reluctant, now, to at last find out whether his own expectation of the caves was ill-founded. “Well, let’s see what we’ve got.”
He unfolded three pieces of paper: his tracing of the photograph, his sketch of the silk map, and his tracing of the antique woodcut. He spread them on the ground and weighted them with pebbles, then placed the notebook, open at Orro’s sketch, beside them. The patterns were not quite identical, and not all the stars shown in one were shown in the others, but as he looked from one drawing to the next, and back, again and again, it was obvious that they were all of the same familiar patch of sky.
The evidence before his eyes was as clear as the jump on a blink comparator: the cliff-men had recorded seven of the stars in the Daughters as green, and the rest as other colours.
“You were right,” he said. “We have a trend.”
He closed his eyes for a moment, and saw a drifting fleet of dots, as if the images he’d looked at were resonating in his optic nerves, fainter and more persistent than an afterimage. He blinked it away and gazed out at the sky.
“In prehistory, the cliff-men saw seven green Daughters. In antiquity, the astrologers of the South saw twenty-seven. In the Dawn Age, mere eights-of-eights of years ago, forty-nine. In the present day, we see fifty-eight with the naked eye, and more with telescopes. And it’s not that some are brighter now than they were then — our ancestors saw stars in the same positions, and saw them as red, yellow, or white. These stars have changed from other colours to green, in the lifetime of the human race.”
Orro jumped up and stalked about for a moment, to the very lip of the cave and back. “Stars evolve,” he said. “From white to yellow to red, isn’t it?”
“I know of that hypothesis,” said Darvin. “The fire analogy. It’s speculative, and going from every other colour to green would knock it right on the head.”
“Not necessarily,” said Orro. “If the green represents a different evolution: life spreading from star to star.”
“Ah, the comet plants!” said Darvin. “The vacuum forests!”
Orro shrugged. “Life is adaptable.” He glared down at Darvin. “You are testing me with your scepticism. You do not feel it yourself.”
“No,” said Darvin. “I don’t.” He folded the sheets of paper between the pages of the notebook and tucked it away. “Tell me what you suspect I suspect.”
Orro squatted down again. “Isn’t it obvious? You suspect that the green tinge is caused by life, yes, but by life in some artificial environment.” He outlined a circle with his hands. “Great globes of glass, perhaps, somehow launched into space, containing complete economies of nature, plants and animals alike, and whatever intelligent inhabitants have built them. That they multiply around a sun, to the extent that eventually they filter all of its light. And that as each sun’s environs become crowded, great ships are launched across the voids between the stars, to repeat the process around another sun. Your comet is of course such a ship, decelerating into orbit around the Sun Himself. In years to come, our sky will be crowded with the green globes, and we ourselves may look forward to meeting the mighty builders of worlds, should they deign to notice such as us.”