“While this world has hitherto received the sketchiest of examinations—” Evalyth was yanked out of a reverie into which the lecture had led her. “—certain facts are clear. Few terrestrial species have flourished; no doubt others were introduced originally, but died off after the technology to maintain them was lost. Man has thus been forced to depend on autochthonous life for the major part of his food. This life is deficient in various elements of human nutrition. For example, the only Vitamin C appears to be in immigrant plants; Sairn observed that the people consume large amounts of grass and leaves from those species, and that fluoroscopic pictures indicate this practice has measurably modified the digestive tract. No one would supply skin, blood, sputum, or similar samples, not even from corpses.” Afraid of magic, Evalyth thought drearily, yes, they’re back to that too. “But intensive analysis of the usual meat animals shows these to be under-supplied with three essential amino acids, and human adaptation to this must have involved considerable change on the cellular and sub-cellular levels. The probable type and extent of such change are computable.”

“The calculations are now complete.” As the computer resumed, Evalyth gripped the arms of her chair and could not breathe. “While the answer is subject to fair probability of success. In effect, Atheian flesh is alien here. It can be metabolized, but the body of the local consumer will excrete certain compounds, and these will import a characteristic odor to skin and breath as well as to urine and feces. The chance is good that it will be detectable by neo-Freeholder technique at distances of several kilometers, after sixty or seventy hours. But since the molecules in question are steadily being degraded and dissipated, speed of action is recommended.”

I am going to find Donli’s murderer. Darkness roared around Evalyth.

“Shall the organisms be ordered for you and given the appropriate search program?” asked the voice. “They can be on hand in an estimated three hours.”

“Yes,” she stammered. “Oh, please—Have you any other…other…advice?”

“The man ought not to be killed out of hand, but brought here for examination, if for no other reason, than in order that the scientific ends of the expedition may be served.”

That’s a machine talking, Evalyth cried. It’s designed to help research. Nothing more. But it was his. And its answer was so altogether Donli that she could no longer hold back her tears.

6.

The single big moon rose nearly full, shortly after sundown. It drowned most stars; the jungle beneath was cobbled with silver and dappled with black; the snowcone of Mount Burus floated unreal at the unseen edge of the world. Wind slid around Evalyth where she crouched on her gravsled; it was full of wet acrid odors, and felt cold though it was not, and chuckled at her back. Somewhere something screeched, every few minutes, and something else cawed reply.

She scowled at her position indicators, aglow on the control panel. Curses and chaos, Moru had to be in this area! He could not have escaped from the valley on foot in the time available, and her search pattern had practically covered it. If she ran out of bugs before she found him, must she assume he was dead? They ought to be able to find his body regardless, ought they not? Unless it was buried deep. Here. She brought the sled to hover, took the next phial off the rack, and stood up to open it.