Like The Killing Joke, the original graphic-novel version of Gotham By Gaslight isn't enough to fill a feature-length animated film (even one as short as this one, clocking in at just over 75 minutes). But, unlike the artless fluff used to pad (and ruin) Joke, the makers of Gaslight crafted an entirely new tale based on the foundations of the novel -- retaining the atmosphere but remaking the plot.

For those of us already familiar with the printed version, it was nice not knowing how it would end.

The tale, based on DC's first Elseworlds book, sets the Batman mythos in Gotham City in the late 19th century. Jack the Ripper is murdering prostitutes in the city's foggy alleyways, and Batman is trying to find him. Unfortunately, his alter-ego Bruce Wayne becomes one of the prime suspects in the case.

Gaslight is much fuller, and its characters more developed, in its movie version. And there are also plenty more characters to go around: Besides Bruce Wayne, James Gordon and Alfred Pennyworth, who are in the book, the animated movie gives us Oliver Twistian prototypes of three Robins (Dick, Jason and Tim), Selina Kyle as a mystery-solving and altruistic showgirl, Dr. Leslie Tompkins reimagined as a kindly nun, bellicose cop Harvey Bullock, Harvey Dent as a Jekyll-and-Hyde prosecutor, Poison Ivy (briefly) as a stripper, and more. Selina Kyle in particular is a key part of the story, aiding Bruce (and Batman) in his investigation.

There are a couple of red herrings, and it's unlikely first-time viewers will guess the culprit's identity early in the film.

Unlike most DC properties, Gotham By Gaslight earned an R rating, although I'm not sure it's entirely deserved. There is minimal swearing and a few hints of skin with no real nudity. It's bloody at times -- as would be expected when your villain is a knife-wielding serial killer -- but there's nothing so excessive or graphic as to explain the rating. Perhaps it was the studio's effort to complete with the likes of Deadpool and Logan?

The animation is good, if not excellent, and the voice work is convincing. Gaslight features Bruce Greenwood as Bruce Wayne and Batman, Jennifer Carpenter as Selina Kyle, Scott Patterson as James Gordon, Anthony Head as Alfred Pennyworth and Yuri Lowenthal as Harvey Dent.

I was still reeling from the studio's ruination of The Killing Joke, but here's a shocker: Gotham By Gaslight is better than the book.