Ray Cummings was one of the most prolific authors science fiction has ever produced. In a career that spanned five decades--from 1919 into the 1950s--Cummings wrote approximately one thousand stories, and he has had in print, at one time or another, over a score of novels and novellas. Today, however, few of his stories are generally available. Most have yellowed with age in the hands of collectors and fans of the pulp magazines for which he mainly wrote. Only a handful of his novels are currently in print, and the amount of critical attention he has received has been scant indeed. The reasons for Cummings's relative neglect are not hard to find: he was one of those pioneers who helped pave the way for others while winning for himself few of the rewards his efforts deserved. Serious science fiction has generally moved away from the kind of romantic adventure...