Batman. He’s been around for almost 80 years, in comic books and movie serials, small screen series and multiple film incarnations. He’s been goofy and gritty and everything in between, and just when you think you’ve got a handle on what Batman can be, along comes something like “Gotham by Gaslight.” Its premise is simple: what if Batman was set in the 1880s? The answer, it turns out, is a delightful twist on both the superhero and detective story.

The plot, it goeth thusly: Gotham is a bustling, growing city struggling to control its seediness as it prepares for a World’s Fair style celebration hosting by late-20-something Bruce Wayne. Alas, the town has a serious problem in the form of Jack the Ripper, who has been killing and mutilating women. And there appears to be a man dressed like a bat who has also been seen at night …