Unwillingly caught in a wager between Heaven and Hell, John Constantine (Keanu Reeves) has nearly had enough. Tired, angry, and dying of lung cancer due to excessive smoking, Constantine longs for death but cannot stop himself from protecting the Earthbound from the demons (including a fun turn from Bush frontman Gavin Rossdale) and angels that prowl the streets. One of those in need of Constantine’s help is Angela (Rachel Weisz), a detective who cannot figure out why her twin sister killed herself, and turns to Constantine when supernatural clues start to hint at the otherworldly mystery she’s found herself in.

The battle between Heaven and Hellr Demons from another worldr Boy, that sounds familiar. And it is, seen in last year’s comic book fantasy, “Hellboy.” “Hellboy” was a promising production, crowded with gruesome visuals, light fantasy touches, and smartly played performances. Nevertheless, the film was weighed down by its elaborate fantasy leanings and out-of-control special effects, ruining what should’ve been a genre grand slam. Eerily, the comic book fantasy “Constantine” feels exactly the same way.

Taken from the comic book “Hellblazer,” the “Constantine” world of demonic sights and angelic sounds is richly envisioned in the film by music video helmer Francis Lawrence. Lawrence is a meticulous visual stylist, constructing a “Constantine” that is all in the details. The director delights in the story’s religious iconography and the potential to try out some video game inspired film-making. The mixture works better than expected thanks to cinematographer Philippe Rousselot’s exciting color scheme and Lawrence’s love for interesting locations, such as Constantine’s bowling alley apartment, situated like an eagle’s nest in the heart of L.A., waiting for trouble to brew.

What Lawrence lacks (like many MTV directors) is a honed sense of story, and he frequently allows “Constantine” to get buried in its complex tale of good vs. evil. The film lacks pace, to be blunt, using copious amounts of dry exposition to catch the audience up on the many characters who help and hinder Constantine’s work. The picture gets tiring almost immediately, and although Lawrence tries to compensate with his pretty pictures, the film cannot shed its inertia no matter how many times Lawrence drags out the slo-mo or the bullet-time. While structured like a traditional fantasy action film, “Constantine” only manages to be truly exciting maybe twice during the running time (Constantine hunting demons with his “Jesus gun,” and his face-off with Satan’s minions in a hospital). The rest of the film is devoted to simply catching the layman up on the exhaustive events and characters that have been hastily nicked from the comic book.

I feel the controversial casting of Keanu Reeves as Constantine pays off wonderfully for the film, for Reeves’s oddball acting choices and Eastwood-like delivery make for an exciting character in an often bleak and lethargic movie. Originally created as a bitter, angry Englishman, Reeves doesn’t even bother with an accent, electing instead to run with the character’s other traits, including chain-smoking and general reticence in dealing with the afterlife. After standing in the long shadow of the two “Matrix” sequels, Reeves is back as his old playful self. It’s a terrific performance. Less encouraging are Lawrence’s other casting choices, which are spectacularly uninspired. Shia LeBouf as a wisecracking teenr Pruitt Taylor Vince as a jittery, sweaty priestr And Peter Stormare, all greasy and full of indication, as Satanr These are very obvious casting mistakes, leaving any hope of something interesting happening in the laps of Reeves, Weisz, and Tilda Swinton, nailing the unwieldy role of sneaky angel Gabriel.

Spending a full 30 minutes trying to wrap up his complicated theological story, Lawrence loses the fire within “Constantine,” slowly lurching toward the climax instead of sprinting. There are plenty of good ideas presented in the finale of the film, with a dynamite resolution for Constantine that insures sequels. Now that Lawrence has gotten his world arranged and his characters straight, the only place for this potential franchise to go is up into the cinema heavens.

Rating: C+