While the team behind the upcoming animated Batman: The Killing Joke have stressed how faithful they have been to the source material, adapting a relatively short graphic novel into a film has meant the addition of new material. One of these additions is a prologue featuring Batgirl. The latest video from DC reveals some new footage of the character, plus an interview with actress Tara Strong. Check it out below:

The Killing Joke will premiere at San Diego Comic-Con later this month, before hitting theaters for a single night on July 25. It then come to Digital HD on July 26, with the Blu-Ray/DVD Combo Pack arriving on August 2.

The film has been made by the team behind the acclaimed ’90s show Batman: The Animated Series, with Kevin Conroy and Mark Hamill reprising their roles as the Caped Crusader and The Joker.

Earlier this month it was confirmed that it would be the first release in Warner’s “DC Universe Original Movie” franchise to receive an R certificate.

In a statement, Warner animation boss Sam Register explained that filmmakers were given the creative freedom to explore the same dark areas as the comic book. “We encouraged producer Bruce Timm and our team to remain faithful to the original story–regardless of the eventual MPAA rating,” he said. “The Killing Joke is revered by the fans, particularly for its blunt, often-shocking adult themes and situations.

“We felt it was our responsibility to present our core audience–the comics-loving community–with an animated film that authentically represented the tale they know all too well.”