Dickens himself took a swing at the mystery genre with his 1870 novel, The Mystery of Edwin Drood, and perhaps laid the groundwork for some of our greatest film mysteries, particularly some of the open-ended films of Alfred Hitchcock. Drood, you see, is left unresolved, the case unfinished, allowing (perhaps forcing) readers to imagine the ending, constructing a resolution that fits the facts as they interpreted them. It was a risky literary trick and few save Dickens could have pulled it off.
If the rest of the research in Thrill-Ride: The Dark World of Mysteries and Thrillers is as good as this titbit, remind me not to read it. Remind me also not to piss off Nick Mamatas with do my research for me type questions…