Beyond observation range, Olear curved back toward Mercury again, and was almost inside its atmosphere when he made a discovery that caused him to lose for a moment his natural indifference, and to clamp his jaws in anger. The current oxygen tank became empty, and when he removed it from the rack and put in a new one he found someone had let out all of this essential gas. The valve of every one of the spare tanks had been opened. Had Olear actually continued on his way to Earth he would have perished miserably of suffocation long before he could have returned to the Mercurian atmosphere. The officer whistled tunelessly through his teeth as he considered this fact.
The visibility was by this time normal; that is, so poor it would have been possible to land very close to the trading station. Olear was taking no chances, however, and came down a good three Earth miles away. The egg-shaped hull sank through the glossy, brilliant treetops, through twisted vines, and was buried in the dank gloom of the jungle. Here it might remain hidden for a hundred years.
he twilight of the jungle was almost darkness. Landmarks were not. But Olear made a few small, inconspicuous marks on trees with his knife until he came to an outcropping rock. He had noticed the scarlike white of it slashing through the jungle from the air, and used it as a guide to direct his stealthy return to the trading post. His belt chronometer told him it would be about time for Morones to get up from his "night's" sleep. A little discreet observation might tell much.
Long before he reached the compound, Olear heard the rushing of the great Blue River in its headlong plunge to the corrosive heat of the desert. And then, through the mists, he glimpsed the white metal walls of the Company sheds.
He climbed a tree and for a long time watched patiently, lying prone on a limb. Blood-sucking insects tortured him, and flat tree-lice, resembling discs with legs, crawled over him inquisitively. Olear tolerated them with stoic indifference until at last his patience was rewarded. Morones was coming out of the compound. He was alone and obviously did not suspect that he was being watched, for he stepped out briskly. Once in the jungle he walked even faster, watching out warily for the panther-like carnivora that were the most dangerous to man on Mercury.
Olear shinned to the ground and followed cautiously. Morones had his ray-tube with him, as any traveler in these jungles did. Olear could and did draw fast, but a dead trader would be valueless to him in his investigation, so he stalked him with every faculty strained to maintain complete silence. Often, in occasional clearings where the brown darkness grew less, he had to grovel on the slimy ground, picking up large bacteria that could be seen with the naked eye, and which left tiny, festering red marks on the skin. Mercury has no snakes.
The trader seemed to be heading for higher ground, for the path led ever upward, though not far from the tossing waters of the river. And then, suddenly, he disappeared.
Olear did not immediately hurry after him. A canny fugitive, catching sight of his pursuer, might suddenly drop to the ground and squirm to the side of the trail, there to wait and catch his pursuer as he passed. So Olear sidled into the all but impenetrable underbrush and slowly, with infinite caution, wormed his way along.