Batman fans could argue all day about which Batman story plays a more iconic role in the Dark Knight's history, Frank Miller's The Dark Knight Returns from 1986, or Alan Moore's Batman: The Killing Joke from 1988. Two things are for sure, though: First, they're both absolute, must-read classics. Second, with elements of The Dark Knight Returns making their way into the not-so-great Batman v Superman: Dawn of Justice, the upcoming animated version of The Killing Joke has a shot at being the better feature adaptation (and yes, we're aware of the animated Dark Knight Returns movie that came out a couple years back).

A new teaser trailer that arrived today offers the first look at what The Killing Joke will look like in animated form, offering peaks at Batman and the Joker in this version, which features Mark Hamill and Kevin Conroy reprising their Batman: The Animated Series voice roles as those characters. We won't know if the darker aspects of the story—including possibly the most senseless act of violence ever seen in a comic book—will remain totally intact until the movie drops sometime this summer. There have been rumors that the movie could feature the character Harley Quinn, which would be a total departure from the source material. 

If you're not familiar with The Killing Joke, the basic plot outline is that the Joker, at his most sadistic, has escaped from Arkham Asylum and kidnapped Commissioner Gordon in order to lead Batman into a trap at an abandoned amusement park. We won't spoil it here, but it's so much more than that. 

A 12-minute featurette on how the new movie was made also briefly made its way onto YouTube today before it was pulled down. You can't watch the whole thing anymore, but someone did edit together all of the actual scenes from the movie that were featured in it, and you can watch that video below.