The Unicorn Murders

For the 150th Crime Classic, this extremely scarce mystery masterpiece by Carter Dickson (John Dickson Carr) is a celebration of what the series is all about; making the greatest, and often very scarce, works of the genre available once more. Part impossible-crime, part Secret Service caper, this is one of the most sought-after Carter Dickson books from the middle of his legendary hot streak of classics in the 1930s.