What is the mystery centered in Jupiter's famous "Red Spot"? Two fighting Earthmen, caught by the "Pipe-men" like their vanished comrades, soon find out.
In one place, a descendant of the Vikings rode a ship such as Lief never dreamed of; from another, one of the descendants of the Caesars, and here an Apache rode a steed such as never roamed the plains. But they were warriors all.
With no more room left on Earth, and with Mars hanging up there empty of life, somebody hit on the plan of starting a colony on the Red Planet. It meant changing the habits and physical structure of the immigrants, but that worked out fine. In fact, every possible factor was covered--except one of the flaws of human nature....
Eighteen men and two women in the closed world of a space ship for five months can only spell tension and trouble--but in this case, the atmosphere was "literally" poisoned.