II
It turned out that it wouldn't have mattered if the Lotus had sent screaming notifications of its presence throughout all nearby space. There were detectors out, of course, but they reported absolutely nothing as the Lotus moved on toward Planet Three. There was static from storms upon the planet. It grew louder as the survey ship approached. But there was no sign of anything alive.
The Lotus cruised some two hundred miles above seas and cloud masses and desert, photographing as she followed a search pattern that covered all the sunlit hemisphere. There were mountains in the tropics which by all the rules of meteorology should have had rain forests at their feet. They didn't. There was a river system which ran like the Nile for a thousand miles or more, through deserts like those of Egypt. There should have been at least a ribbon of vegetation along its banks. There wasn't. Where it reached the sea was an enormous delta.
A drone went down and reported temperatures and humidity and the composition of the atmosphere, and the radiation background count. One would have thought the records those of Earth. The background count was a trifle high—3.9 instead of 3.6—but there was eighteen per cent of oxygen in the atmosphere. The only oddity, there, was nearly a full per cent of helium. When the drone came up it brought samples of soil and sea water. There was no life in either. The soil was mostly mineral dust, but an electron microscope disclosed abraded fractions of pollen grains and the like. The sea water sample had evidently been picked up by the drone's dredge from some shallow. There were tiny, silicious shells in it. Plankton. They had been alive, but were so no longer.
"I think," said Nolan, "that I make a landing. Right?"
The skipper said crossly, "Yes. You're the best man for it. You notice things. But I doubt you'll learn very much." He tapped the written report that the radiation background count was 3.9. "It happened a long time ago. A long, long time ago!" Then he said with a totally unsuccessful attempt at humor, "Try and find out that it was bug-eyed monsters, eh? It looks too much like Earth! I'd rather blame monsters than men!"