"The purpose of a contemplated human action is always the attainment of a desired subjective experience. But a subjective experience is desired both in terms of intensity, and in terms of duration. For an individual the temptingness of different degrees of intensity-of-experience is readily computed. However, the temptingness of different durations is equally necessary for the computation of the probability of a given individual performing a given action. This modification of desirability by expectable duration depends on the individual's time-sense: its acuity and its accuracy. Measurements of time-sense—"
Probability and Human Conduct
Fitzgerald
Two days later Calhoun found a cultivated field and a dead man, but before that he found only bewilderment. Before leaving the Med Ship, he very carefully monitored all over again the entire radiation spectrum for man-made signals. There were no communications in the air of Maris III—which on the face of it was proof that the planet was uninhabited. But the ship's external microphones picked up a rocket roar in mid-morning of the day after Calhoun's landing. By the time the sound reached the ground, of course, the rocket itself was far below the horizon; but Calhoun saw the faint white trail of its passage against the blue of the sky. The fact that he saw it, in daytime, was proof that it was within the atmosphere. Which, in turn, said that the rocket was taking photographs from high altitude for signs of the crater the Med Ship should have made in an uncontrolled landing.
The fact of search proved that the planet was inhabited, and the silence of the radio spectrum said that it wasn't. The absence of traffic in the city said that it was dead or empty, but there were people there because they'd answered Calhoun's hail, and tried to kill him when he identified himself. But nobody would want to destroy a Med Ship except to prevent a health inspection, and nobody would want to prevent an inspection unless there was a situation aground that the Med Service ought to know about. But there should not possibly be such a situation.
There was no logical explanation for such a series of contradictions. Civilized men acted this way or that. There could only be civilized men here. They acted neither this way nor that. Therefore—the confusion began all over again.
Calhoun dictated an account of events to date into the emergency responder in the ship. If a search-call came from space, the responder would broadcast this data and Calhoun's intended action. He carefully shut off all other operating circuits so the ship couldn't be found by their radiation. He equipped himself for travel, and he and Murgatroyd left the ship. Obviously, he headed toward the city where whatever was wrong was centered.
Travel on foot was unaccustomed, but not difficult. The vegetation was semi-familiar. Maris III was an Earth-type planet and circled a Sol-type sun, and given similar conditions of gravity, air, sunlight, and temperature-range, similar organisms should develop. There would be room, for example, for low-growing ground-cover plants and there would also be advantages to height. There would be some equivalent of grasses, and there would be the equivalent of trees, with intermediate forms having in-between habits of growth. Similar reasoning would apply to animal life. There would be parallel ecological niches for animals to fill, and animals would adapt to fill them.
Maris III was not, then, an "unearthly" environment. It was much more like an unfamiliar part of a known planet than a new world altogether. But there were some oddities. An herbivorous creature without legs which squirmed like a snake. It lived in holes. A pigeon-sized creature whose wings were modified, gossamer-thin scales with iridescent colorings. There were creatures which seemed to live in lunatic association, and Calhoun was irritably curious to know if they were really symbiotes or only unrecognizable forms of the same organism, like the terrestrial male and female firefly-glowworm.
But he was heading for the city. He couldn't spare time to biologize. On his first day's journey he looked for food to save the rations he carried. Murgatroyd was handy, here. The little tormal had his place in human society. He was friendly, and he was passionately imitative of human beings, and he had a definite psychology of his own. But he was useful, too. When Calhoun strode through the forests which had such curiously un-leaflike foliage, Murgatroyd strode grandly with him, imitating his walk. From time to time he dropped to all four paws to investigate something. He invariably caught up with Calhoun within seconds.
Once Calhoun saw him interestedly bite a tiny bit out of a most unpromising looking shrub-stalk. He savored its flavor, and then swallowed it. Calhoun took note of the plant and cut off a section. He bound it to the skin of his arm up near the elbow. Hours later there was no allergic reaction, so he tasted it. It was almost familiar. It had the flavor of a bracken-shoot, mingled with a fruity taste. It would be a green bulk-food like spinach or asparagus, filling but without much substance.