Publisher's Synopsis
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. Paul Frederick Ernst (1899 - 1985) was an American pulp fiction writer. He is best known as the author of the original 24 "Avenger" novels, published by Street and Smith Publications under the house name Kenneth Robeson.