The Martian Cabal

Sime Hemingway is new to Mars. A member of the Interplanetary Flying Police, patrolling the lonely reaches of space, he was normally a cool customer. His first night on the red planet was different, he was on edge, unable to sleep and inexplicably on guard.
R. F. Starzl was an American science fiction author and regular of the pulp sci-fi magazines during the Golden Age of Science Fiction. He was called a "master" by the pioneer of space opera E. E. Smith.