The Killing Joke, written by Alan Moore and illustrated by Brian Bolland, is one of the finest Batman/Joker stories ever released in graphic novel form.

The Killing Joke, adapted for the screen by Brian Azzarello and directed by Sam Liu, falls somewhere between mediocre and pretty awful.

Where did it go wrong? In so many places.

Let's begin with the prelude, a nearly 30-minute-long first act written solely for the film. An attempt by Azzarello to provide more of a backstory for Batgirl and more context for her relationship with the Batman, it plays like a mediocre episode of any number of Batman cartoons, albeit more violent and sexual than most. Besides defining Barbara "Batgirl" Gordon as an insecure shadow of her mentor, it gives us a lukewarm villain, a stereotypical gay friend and a hackneyed "time of the month" joke when Batgirl's in a bad mood. Also, it introduces out-of-nowhere Bat-sex between the heroes, which is about as awkwardly staged as Batman's skittish "Hey..." and Batgirl's loud "It was just sex!" proclamation the first time they speak afterwards.

Then the Joker busts out of Arkham Asylum, and the animated movie finally begins to tell Moore's gritty, well-crafted tale.

Or so they would have you believe.

But, while the basic framework of the story is the same, the details and nuances are lost. The Joker's hallmark speech about the common man is cut, as are scenes of the Batman's frantic search for the Joker after discovering his absence from Arkham. A song-and-dance number that's implied in the comic is brought to life here and it's -- well, let's be honest, it's silly and out of place. The final clash between Batman and Joker at the end is watered down, and the ultimate joke loses its zest.

Filmmakers get even the tiny details wrong. There's a poignant scene in the book where Batman visits Barbara Gordon in the hospital. She calls him by name, and her fear for her father -- in spite of her own crippling injury -- is a powerful moment. Here, the scene is far more static and, although in this version the two heroes have shared intimacy, the implication is that she doesn't even know his real name.

Unlike a recent animated adaptation of Frank Miller's The Dark Knight Returns, The Killing Joke doesn't try very hard to match the art style used by Bolland in the graphic novel. The movie animation, by comparison, looks bland.

And, while Kevin Conroy and Mark Hamill are tried and true voice actors as Batman and Joker, many of the voices used here don't suit the characters. Commissioner Gordon, voice by Ray Wise, in particular sounds far more frail than his physique would have you believe.

Overall, I found watching The Killing Joke a disappointment -- although it did whet my appetite to read the book again to see the story told properly.

Read Tom Knapp's reviews of The Killing Joke and The Dark Knight Returns graphic novels, and Mary Harvey's review of The Dark Knight Returns two-part animated movie.