First Edition. Clemens Gretter dustjacket art. Detective Ace Cole uses a deck of cards to solve a series of murders. Extremely scarce mystery, presumed to be author's only book. No copies on WorldCat. Very Good, firmly bound volume, with mysterious cloth discoloration at spine and fore-edge of front cover, in Fine (pristine) dustjacket that had been stored separate from the book these many years (from an archive of Phoenix Press material).