"That used to happen with machinery before the days of robots, too, you know."
"We don't even know where we're heading."
"We don't need the robot for that. I've been checking the course, and we're obviously heading for Titan."
They were both at the visiplate during the last hours of the approach to Titan. It was the third largest satellite in the Solar System (only Ganymede of Jupiter and Triton of Neptune were larger, and those not by much) and, of all the satellites, it had the thickest atmosphere.
The effect of its atmosphere was obvious even from a distance. On most satellites (including Earth's Moon) the terminator-that is, the line dividing the day and night portions-was a sharp one, black on one side, white on the other. But it was not so in this case.
Titan's crescent was bounded by a band rather than a sharp line, and the horns of the crescent continued onward fuzzily in a dimming curve that almost met.
"It has an atmosphere almost as thick as Earth's, Bigman," said Lucky.
"Not breathable?" said Bigman.
"No, not breathable. It's mainly methane."
Other ships were crowding in now, becoming visible to the naked eye. There were at least a dozen, herding them down the spaceways to Titan.
Lucky shook his head. "Twelve ships to spare for this one job. Great Galaxy, they must have been here for years, building and preparing. How can we ever get them off again, short of war?"
Bigman attempted no answer.
Again the sound of atmosphere made its unmistakable way into the ship,.the high-pitched keening of thin wisps of gas whipping past the streamlined hull.
Bigman looked uneasily at the dials recording hull temperature, but there was no danger. The robot at the controls was sure-handed. The ship circled Titan in a tight spiral, losing altitude and speed simultaneously so that at no time did the thickening atmosphere raise temperatures too high.
Again Lucky glowed with admiration. "It will manage it without fuel at all. I honestly think it could bring us down on a half-credit piece, with atmosphere as the only brake,"
Bigman said, "What's good about that, Lucky? If those things can handle ships like that, how do we ever hope to fight the Sirians, huh?"
"We'll just have to learn to build our own, Bigman. These robots are a human achievement. The humans that did the achieving are Sirians, yes, but they are human beings, too, and all other humans can share pride in the achievement. If we fear the results of their achievement, let's match it ourselves or more than match it. But there's no use denying them the worth of their accomplishment."
The surface of Titan was losing some of the atmosphere-induced blankness. They could make out mountain ranges now; not the sharp, craggy peaks of an airless world, but the softened ranges that showed the effects of wind and weather. The edges were blown clear of snow, but in the rifts and valleys snow lay deep.
"Not snow, really," said Lucky, "frozen ammonia."
All was desolate, of course. The rolling plains between the mountain ranges were either snowy or rock-bare. No life of any kind appeared. No rivers or lakes. And then…
"Great Galaxy!" said Lucky.
A dome had made its appearance. A flattened dome of a type familiar enough on the inner planets. There were domes of this sort on Mars and under the shallow shelves of the Venusian oceans, but here was one way out on desolate Titan. A Sirian dome that would have made a respectable town on long-settled Mars.
"We've slept while they've built," said Lucky.
"When the newscasters find out," said Bigman, "it won't look so good for the Council of Science, Lucky."
"Unless we break this thing, it won't. And the Council doesn't deserve better. Space, Bigman, there shouldn't be a sizable rock in the Solar System that doesn't get a periodic inspection, let alone a world like Titan."
"Who would have thought… "
"The Council of Science should have thought. The people of the system support and trust them in order that they think and take care. And I should have thought too."
The voice of the robot broke in upon them. "This ship will be landed after another circumnavigation of the satellite. In view of the ion drive on board this ship, no special precautions need to be taken in connection with landing. Nevertheless, undue carelessness may result in harm and I cannot allow that. I must therefore request you to lie down and strap yourselves in."
Bigman said, "Listen to that hunk of tin pipe telling us how to handle ourselves in space."
"Just the same," said Lucky, "you'd better lie down.
He's likely to force us down if we don't. It's his job not to allow harm to come to us."
Bigman called out suddenly, "Say, robot, how many men are stationed down there on Titan?"
There was no answer.
Ground came up and up and swallowed them, tunneling them downward. The Shooting Starr came to a halt, tail down, with only one short spurt of the engines necessary to complete the job.
The robot turned away from the controls. "You have been brought safely and without harm to Titan. My immediate task is done and I will now turn you over to the masters."
"To Sten Devoure?"
"That is one of the masters. You may step out of the ship freely. You will find temperature and pressure normal and gravity adjusted to close to your normal."
"May we step out now?" asked Lucky.
"Yes. The masters are waiting."
Lucky nodded. Somehow he could not quite suppress the beginning of an odd excitement. Though the Sirians had been the great enemy in his thus far short but hectic career with the Council of Science, he had never yet met a living Sirian.
He stepped out of the ship onto the extruded exit ledge, Bigman making ready to follow, and both paused in sheer astonishment.
9. The Enemy
Lucky had his foot upon the first rung of the ladder that would carry them to ground level. Bigman peered over his large friend's shoulder. Both were open-mouthed.
It was as though they were stepping out upon the surface of the Earth. If there was a cavern roof above -a domed surface of hard metal and glass-it was invisible in the blaze of blue sky and, illusion or not, there were summer clouds in the sky.
Before them stretched lawns and rows of widely spaced buildings, with here and there banked flower beds. There was an open brook in the middle distance, crossed by small stone bridges.
Robots by the dozens were hurrying, each on his own way, each on his own business, with machinelike concentration. Several hundred yards off, five beings- Sirians!-stood in a cluster and watched curiously.
A voice broke in sharply and peremptorily on Lucky and Bigman. "You up there. Come down. Come down, I say. No dawdling."
Lucky looked down. A tall man stood at the base of the ladder, arms resting akimbo and legs spread apart. His narrow olive-complexioned face looked up at them arrogantly. His dark hair was cropped into a mere fuzz in the Sirian fashion. In addition, his face bore a trim and well-kept beard and a thin mustache. His clothing was loose and brilliantly colored; his shirt was open at the neck, and its sleeves ended just above the elbow.
Lucky called, "If you're in a hurry, sir, certainly."
He swung about and dropped down the ladder, hands only, his lithe body twisting with effortless grace. He pushed himself away from the hull and dropped the final twelve rungs, twisting as he did so to land face to face with the man on the ground. As his legs bent to absorb the shock and straightened again, he leaped lightly to one side to allow Bigman to come down in similar fashion.
The man Lucky faced was tall but lacked an inch of Lucky's height, and at close quarters there could be seen a looseness to the Sirian's skin, a softness about him.
He scowled and his upper lip lifted in a grimace of contempt. "Acrobats! Monkeys!"
"Neither, sir," said Lucky with quiet good humor. "Earthmen."
The other said, "You are David Starr, but you are called Lucky. Does that mean in the Earthman lingo what it means in our language?"