Before I saw “Constantine,” I considered it one of the biggest blunders in the fashionable trend of comic book adaptations.

Only Hollywood would cast one of the flattest actors imaginable to play a character so complex and captivating that he literally bleeds off the comic book panels he inhabits. Fortunately, I was wrong. The movie “Constantine” was not only salvageable, but ultimately enjoyable.

Make no mistake, Keanu Reeves is horribly miscast in the role of John Constantine. The role calls for a blonde-haired, middle-aged Brit, and Reeves is not any of those things. Fortunately, Reeves manages to pull off the elements that have made John Constantine so enjoyable in the comic book, capturing his sardonic wit and indignant air. Another preserved comic book quality is Constantine’s “devil-may-care” attitude, which gives Lucifer himself a run for his money.

Even after 200-plus issues of his own series, “Hellblazer,” John Constantine remains a mystery. The movie dumbs down some of the complexity surrounding Constantine, but it still carries his moral ambiguity.

As a child, Constantine can see both divine and demonic forces gridlocked in conflict in the shadows of everyday life. After a botched suicide, Constantine is dead, but only for two minutes before he is resuscitated. Those two minutes are enough to get him barred from heaven. As a result, Constantine spends the better part of his life sending offending demon half-breeds back to hell in an effort to get on God’s good side. And it doesn’t seem to be working.

Soon, Constantine is embroiled in a plot involving police officer Angela Dodson (Rachel Weisz), the apparent suicide of Dodson’s twin sister, Isabella, and the machinations of both the sadistic demon Balthazar (Gavin Rossdale) and the equally ruthless Gabriel (Tilda Swinton).

While the movie perfectly captures the atmosphere of the Vertigo/DC Comic, the plot is somewhat poorly stitched together. All of the scenes are rather enjoyable, but they don’t always fit together in a cohesive manner.

In the latter half of the movie, Constantine wields a fire-breathing shotgun, a mystical weapon that loses all appeal after it is fired a few times. Also, the gun downplays Constantine’s ability to outsmart his adversaries, which is really the crux of the movie. Later sequences involving the holy shotgun look more like “Blade” than “Constantine.” Fortunately, Constantine loses the weapon by the film’s enjoyable and unorthodox climax.

Overall, “Constantine” is an enjoyable movie that is neither disposable nor profound. The character of John Constantine is a compelling mix of self-serving cynicism and self-sacrificing bravery. It is a motif that only the finest comic book writers can maintain, and only time will tell if a “Constantine” film franchise can be just as successful.