This volume is about Batman vs. Jack the Ripper.
This is the first "Elseworld" story, Gotham by Gaslight takes place, retroactively, on Earth-19. Set in the 1880's, Batman must track down and defeat Jack the Ripper.
It falls into the modern "steam punk" genre, in which a modern or future set of characters exist in a 19th century Victorian England setting.
It has a sequel: Batman: Master of the Future.
Ranked #9 in Wizard Magazine's list of "100 Best Single Issue Comics Since You Were Born".
Non-U.S. Collected Editions