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.
Robert E. Howard, Henry Kuttner, H. P. Lovecraft, Mary Elizabeth Counselman, Miriam Allen DeFord, Paul Compton, Edmond Hamilton, Lloyd Arthur Eshbach, Theodore Sturgeon, Jamie Wild, C. L. Moore, Leah Bodine Drake, Manly Wade Wellman, Pearl Norton Swet, August Derleth, Dorothy Quick, Warren Lapine, Ronal Kayser, H. Beam Piper, Earl Peirce, Jr., Frank Belknap Long, Paul Ernst, Seabury Quinn, David H. Keller, Greye La Spina & Franz Habl
Kimberly B. Richardson, Frederick C. Davis, Paul Ernst, Arthur Leo Zagat, Chandler H. Whipple, G.T. Fleming-Roberts, Wyatt Blassingame, Hugh B. Cave, Wayne Rogers, Henry Treat Sperry & John H. Knox