EERIE MYSTERIES was a short-lived weird menace pulp which lasted a mere four issues, beginning with the August 1938 issue and ending with the April/May 1939 issue.  At that, it was more successful than its precursor, EERIE STORIES, which lasted all of one issue.  All issues of EERIE MYSTERIES featured cover art by prolific artist Norman Saunders.  Ralph Powers, purported author of "When It Rained Corpses" is a house name used in several of the pulps published by Ace, as were several names which appeared on the contents pages of EERIE MYSTERIES, including Ronald Flagg and Cliff Howe.  Indeed, Norman Daniels stands out on the contents page for November 1938 by probably being the only real author listed.  Several stories in EERIE MYSTERIES were reprinted from other Ace pulps, such as TEN DETECTIVE ACES, with titles and authors changed.