Detective No. 27 is a graphic novel by Michael Uslan and Peter Snejbjerg, published by DC Comics as an Elseworlds tale, detailing the adventures of a Bruce Wayne that never became The Batman, but instead became a detective in a secret society. He is the 27th detective in the agency, thus giving the graphic novel its title. (Which is, of course, also a reference to Batman's first appearence, in Detective Comics #27).
The story involves a complicated plot dating back to the assassination of Abraham Lincoln, by a group of confederate sympathizers who wish to gain revenge by bringing great geneticists into developing a super virulent poison that will wipe out a major city. The story is set in the 1920s and 1930s, as Bruce Wayne, who saw his parents murdered, returns to Gotham City after years of study. Instead of becoming a Super-Hero, he is ushered into the secret fraternity of detectives, and plays a vital role in foiling the evil scheme to poison all of Gotham City.
As a story, it works fine, and the plot is fairly involved and involving. And the historical nature of the story gives some nice surprises: if you've ever wanted to watch Bruce Wayne and Babe Ruth team up (with attendant Bat Man jokes), this is probably the only place to do it. As a Batman story, the story doesn't actually work, though. The key to Batman's characterization is a great rage that is only kept under control with an iron code of ethics and self-discipline, which results in a total competency and an almost super-human insight. This story doesn't seem to have the key to Batman's character, and is instead merely a tale of a man who shares some of Bruce Wayne's biography.