The Impossible World, by Eando Binder (epub/Kindle)
In 2050 A.D., the Earth spaceship Tycho lands on Iapetus, the eighth moon of Saturn, nine hundred million miles from the sun. Hugh Benning, mineraologist, and his men explore the deserted world. When they come to a natural cave, the men begin to stagger and fall. Benning disappears into the mouth of the cave as the pilots gather up the limp forms and retunr them to Earth. If they aren't dead and they aren't alive, perhaps they are in a state of suspended animation. Can they be revived to shed light on...the menace of Iapetus?