Hamilton Cleek, once known to Scotland Yard as The Vanishing Cracksman is a reformed crook turned detective. He has a gift for both deduction and impersonation, a curious combination of Sherlock Holmes and Peter Sellars, which he uses to solve mysteries. After a long Channel crossing, Cleek drives a lady home only to discover her aunt has been murdered. But the mystery has only just begun. It leads to a mysterious and sinister chain of events, which Cleek and Superintendent Maverick Narkom of Scotland Yard attempt to unravel, with, of course, the help of the irrepressible and ever-hungry Dollops, Cleeks cockney sidekick. As excitingly improbable a detective story as ever baffled and allured the breathless reader, The Riddle of the Purple Emperor has all the thrills of adventure and murder and hate and love embroidered on the groundwork of a plot as precisely worked out as a problem in mathematics.