Darvin looked sidelong at his friend with admiration. “What a delightful fancy!” he said. “No, really. And it is a possibility, I concede. But as scientists rather than writers of engineering tales, we should seek explanations in the work of nature rather than the hand of mind whenever possible. I think it’s life, certainly, and that it is spreading, but I think it may be an entirely natural process. Because if life — a hardy spore that escaped the atmosphere, perhaps — were to gain a foothold on some rock or comet in space, it could spread. As it did so it would be modified by evolution, and its own actions would modify the paths of the bodies on which it grew. A decelerating comet seems much more plausible if we imagine its out-gassing to be controlled — mindlessly, it is true — by some life within.”
Orro was shaking his head. “A journey from star to star would take millions of years. We’re seeing stars changing over eights-of-eights.”
“I’m not talking about passive drifting, like spores or downy seeds on the wind. I imagine some much faster propulsion.” He swept his arms in a circle wider than the one Orro had outlined a moment earlier. “A sail of some sort.”
“Propelled by what wind?”
“Light exerts a pressure in vacuum,” said Darvin. “The Sun gives forth a fiery stream of other particles.”
“Too weak a one for star-sailing,” Orro said. “No, Darvin, we are looking at… spaceships. And artificial worlds in numbers that beggar the imagination.”
Darvin felt his knees shake. He did and did not want to believe it.
Orro took two strips of dried meat from his provisions pack, passed one to Darvin and started chewing on the other. “Here is an idea for further research. We find out the distance of each of the stars charted in the Daughters region, green or not. We can see whether the earlier green stars are closer together than the later ones. From this we can see if a spread from star to star is actually happening.”
Darvin nodded. “Obvious,” he said. “Go on.”
“And we check whether spectrographic analyses exist for any of these stars. If we were to find that they still show traces of the spectra from stars with lights of other colours than green and they match the ancient records, we’d have made our case. And then we should find out the composition of the green light itself.”
“Oh, I know what that is,” said Darvin. “Its spectra show the lines of oxygen, carbon, and nitrogen.”
Orro jumped up again. “But these are the constituents of life itself!”
“Yes,” said Darvin. “And that’s one reason why astronomers regard life around these stars as possible. That is not the surprise. The surprise, if we are right, is that we have evidence that it is spreading. Or at least,” he added, struck by an intellectual scruple, “that it is arising around more and more stars.”
“Why has more not been made of this?” Orro almost shouted. “Life around the stars would be the most significant finding of astronomy!”
Darvin thought about it, chewing on the strip. “Hmm,” he said. “I suppose because it’s all so wretched hypothetical, old chap, and so embarrassing to seem to confirm the myths of religion and the… sensationalism of the vulgar.”
He smiled at Orro and gestured at him to sit down. “Let’s eat,” he said. “And then let’s take wing, and fly over the high desert, and find some place of comfortable vantage to wait for nightfall and count the Daughters for ourselves.”
It goes all the way down, Darvin thought to himself. Out here in the pitch black of a night before either of the moons had risen, away from lights and smoke, the sky came all the way down to the ground. You could see stars blink into view as they rose above the horizon, and to the west you could watch them disappear beneath it. And in between, in the vault above, the sky was packed with stars. The whole sky shimmered with the massed twinkling in multiple colours. The Shining Path spanned the zenith. The constellations, lost in the crowd, were more difficult to identify than they were at night in Five Ravines.
The Queen dominated the ecliptic, the Warrior a distant second. Between the Shining Path and the ecliptic the Daughters shone green across the eastern sky. He had counted the fifty-eight, and wasn’t sure there weren’t more. Behind the visible green stars was a greenish haze. In the midst of them, like a ruby among emeralds, glowed the Blood-drop, known to astronomy as Stella Proxima, the Nearest Star.
Orro was staring at it. “That’s where your comet came from,” he said. “Stella Proxima.”
“If it was a spaceship,” said Darvin, “I suppose it must have done.”
“No!” said Orro. “There is no supposition about it. Can’t you see, man, that’s where the trajectory goes back to?”
“I can’t see it,” said Darvin. “I’m no mathematician. But I have no doubt you can show me it, when we get back.” He shivered. “Speaking of which.”
“The passenger cars aren’t running,” said Orro.
“What?” said Darvin, feeling stupid. “But the overnight mail—”
“Travels in what are known, technically, as mail cars,” said Orro. “So here we stay.”
“We can’t!” said Darvin, looking around. He could just about see. He could hear things.
“How are you going to get back?” jeered Orro. “Fly?”
Darvin wrapped his wings around himself. “What else can we do?”
Orro’s eyes showed their whites in the starlit dark. “You’ve never spent a night out of cover?”
“No.”
“I have,” said Orro. “Let me show you.”
He vanished into the dark. A few minutes — Darvin confirmed the time by the wheeling of the stars, but it seemed longer — he returned with a double armful of brushwood. He stacked some and set fire to it. Rising sparks replaced the stars, and the crackling of twigs muffled the distant scurries.
“We have some food left,” he said. “And water.”
“Not much water.”
Orro flourished a glass flask. “Firewater,” he said. “So called because it keeps us warm.”
Darvin joined him in a huddle over the small fire. Orro began turning a strip of dried meat above the flames. The smell became appetising.
“Where did you learn all this?” Darvin asked.
“Military training.”
“Ah,” said Darvin. He bit off a chunk of the now much more palatable meat and handed the remainder back. “This is a delicate question,” he said. “I hope I don’t offend.”
Orro waved the strip, munching. “Go ahead.”
“I didn’t know ironmongers’ sons had military training.”
“They don’t, generally,” said Orro. He unstoppered the firewater flask, swigged and passed it to Darvin. “But ‘scientific civil servant’ is a rank of nobility. Hence military training, from the Academy onward.”
The firewater burned in Darvin’s mouth and down his throat. “You’re a nobleman?”
“Indeed I am,” said Orro. “And a not very competent sabreur. I preened myself on being a somewhat more adequate scout.”
Darvin laughed. “I thought that to be a noble one had to own land.”
“Oh, I do,” said Orro. “I am entitled to the rent of an acre.”
“How much does that come to?”
“Nothing,” said Orro. “It’s a patch of uninhabited and barren desert.” He laughed. “Some have become rich from such fiefs. They found rock-oil.”