Whether you agree or not that Sherlock Holmes was the greatest detective who never lived, there is little evidence here that his maker, Conan Doyle, could have been admitted to the first rank of investigators--unless enthusiasm for the grisly be the prime qualification. In a rehash of cases that interested Conan Doyle enough to publicly comment on, Costello (Jules Verne, 1978, etc.) begins with Conan Doyle's childhood enthusiasm for Madame Tussaud's (""I am delighted with the room of Horrors and with the images of the murderers""); documents his subject's membership in the secretive Crimes Club, a discussion group that concentrated on the infamous, such as Jack the Ripper (conan Doyle felt more should have been done with the Ripper's handwriting samples); follows Conan Doyle from England to America to South Africa to Australia, and recaps the mysteries he came in contact with in each. Costello recounts Conan Doyle's appearance at the Crippen trial; his Scotland Yard communication over the ""Brides in the Bath"" murders; his incontrovertible proof that George Edalji was innocent (although the Home Office didn't seem to care); his pesky snooping into the Agatha Christie disappearance (Conan Doyle, out of deference to a fellow author, knew more than he told about her motive); and his opinion of Sacco and Vanzetti (""the two Italians were executed not as murderers but as anarchists""). Costello cites a dozen or more cases, some seeming to reflect his own interest more than Conan Doyle's, then ventures into dicey territory: Conan Doyle's spiritualism and his trust in clues/solutions rendered by various prominent mediums. An incorrigible tendency toward abbreviating Conan Doyle's views to promulgate his own diminishes Costello's well-researched quasi-biography, which ultimately makes the crimes more interesting than the crimewriter.