The Immortals of Mercury

Cliff Howard regretted that he had decided to explore the territories of Mercury alone, contrary to the warnings of the head of Johnson's first scientific expedition... Local savages Dlacus managed to capture an earthling and were preparing to fry him alive with the help of monstrous Groko lizards... However, waking up in an unusual place, Howard learned that that he was saved by super-developed Oumnis - ancient inhabitants from the depths of Mercury... One of them, Agvar, explains some things to the earthling, but the head of Oumnis Ounavodo condemns him to death for the sake of producing muffa-alloy - a protective coating for the internal chambers of almost immortal Mercurians. But Howard doesn't even think about accepting the role of the victim...