Quest on Phoebe

Savagely, Ron Farr tore and blasted through the Saturnian moon's jungle, snarling at the timid natives to keep their distance. He sought eternal life—and they might get in his way....
Others before him had tried—and failed. Ron Farr meant to succeed. He had come fully prepared to surmount whatever obstacles might lie in his path, to conquer the dread guardian jungle and its unknown terrors and return triumphant to Earth, master of destiny and possessor of undreamed of power.
Farr knew the obstacles would be there, for he sought the secret of eternal life, the fabulous elixir that lay hidden somewhere on Phoebe, enigmatic moon of Saturn, and there was little doubt in his mind that the ancients of the ringed planet had made ample provision for the protection of this, their most cherished treasure. One by one, a dozen eager men had gone in quest of the secret—none had returned. That was enough proof for him.
But, in spite of this grim evidence, Farr was not afraid. He was ready to face death itself, if need be, to gain the goal that would prostrate the world at his feet. He was ready to face death, but he had taken every precaution against it. For instance, in selecting a likely landing place, he had shunned the area in which the life secret was reputed to be, for his instruments had detected some sort of force-field above the region. Invisible to the eye, the field would have crushed his ship in an instant, had he attempted to enter the area without consulting the instrument panel.
The region was boxed in on three sides by sheer cliffs, leaving but one avenue of approach. That was through the dense and foreboding jungle that stretched for miles across the face of the canyon.
Farr had taken that avenue. Now, as he stepped from his ship and regarded the jungle's fringe with clear, steady eyes, he looked anything but the ruthless brigand he was.
Straight black hair, high forehead, firm, unsmiling lips—all gave the man the appearance of a gentlemanly scholar. But behind those austere features lurked a cunning, treacherous mind. That he should be seeking the secret of eternal life in so surreptitious a manner was proof that the gaining of it would be put to his own advantage, and not to the benefit of mankind.