If you were wondering where Christopher Nolan found inspiration for his mega blockbuster film, "The Dark Knight Rises," look no further than "The Dark Knight Returns," a series of comics penned by Frank Miller in the 1980s.

It tells the story of an aging Bruce Wayne who's been retired as Batman (sound familiar?) for 10 years only to return when Gotham City needs him most.

"The Dark Knight Returns" can be easily found in graphic novel form now, but when it first hit comic book shops in the 1980s as a four-part series it turned the Batman character upside down, and in a good way. Miller's depiction was dark ... very dark, and eye-opening.

Over the years, fanboys have begged for a movie company to bring "The Dark Knight Returns," to the big screen, but it hasn't happened.

Warner Bros. took a different route - a straight-to-video animated film - and the result is impressive. Warner Bros. made the film in two parts, Part 1 on DVD and Blu Ray was released on Tuesday, and for good reason. The first film is 1 hour, 16 minutes, which is long for an animated film.

Do the math. Producing an animated film that would have likely been close to two-and-a-half hours doesn't make sense. On one hand, die-hard Batman fans have to be disappointed they must wait until early 2013 for Part 2, but it will be worth it. Part 1 is must-see viewing for any Batman fan.

Warner Bros. has clearly taken its time transforming Miller's iconic graphic novel to film. A few scenes were eliminated completely (most likely because of time constraints), and some of the intense violence and language from the pages is toned down a bit for home viewing but not much.

If the first fight between Batman and Bane in Nolan's "The Dark Knight Rises" had your jaw dropped to the floor, the two fights between an even older Caped Crusader (he's at least 50 in "Returns") and the over-the-top, but super-cool mutant leader in Part 1 is more stunning. The final fight has the best line of the film. Batman as he's taking on the mutant leader: "You don't get it boy. This isn't a mudhole. It's an operating table, and I'm the surgeon." Get the point? It's the most violent animated film I've ever seen.

As for why Wayne returns to wear the cape and cowl, the obvious answer is the presence of old nemesis and friend Harvey Dent/Two-Face and a mutant gang that threatens to take over Gotham. Looking beyond that, it's about Wayne not being able to escape his inner Batman (again, sound familiar?) Why he's been retired for 10 years is hinted at, but never fully explained. Jason Todd, the second Robin after Dick Grayson, was murdered by the Joker, and a reference to that popular story from the '80s is the likely reason why Batman retired in the first place.

That's plenty to take in for Part 1, which ends with a teaser to the Dark Knight's ultimate foe, the Joker, for Part 2.

Two disappointments:

- No voice overs by Peter Weller (Robocop), the voice of Batman. One of the most iconic lines in the graphic novel of "Returns" is when Wayne makes his return as Batman. He does so on a rainy Gotham night, and as he's jumping off a rooftop he says to himself, "The rain on my chest is a baptism ... I'm born again." We don't get that fantastic line and others from the graphic novel in the film version.

- Blu Ray extras, especially the touting of the digital version of the graphic novel. Instead, it's only a few pages. How lame. There is a cool preview of Part 2 of "Returns," but not much else worth spending your time on. That's not the reason to buy this DVD or Blu Ray. The film itself is well worth the price.

- Mark Podolski | @mpodo