John Constantine isn't just world weary. He's netherworld weary.

He clamps a glass over a spider crawling across his desk, then blows cigarette smoke inside the little prison and says, "Welcome to my world."

It turns out that a lifetime of seeing horrific things most people can't will leave a guy a heavy smoker and drinker with the flat delivery of Keanu Reeves. Reeves plays one of the comic-book world's most intriguing antiheroes in an adaptation that isn't the massive screw-up fans rightfully expected, but has a cool-to-silly ratio that's just barely acceptable.

Constantine is a sort of freelance exorcist who gets called in for the cases so nasty they would have made "Exorcist" fathers Merrin and Karras void in their vestments. He deports demons back to hell in a campaign to stave off his own damnation for a mortal sin from his youth — which sprang from his gift/curse of being able to perceive the "half-breed" angels and devils walking among us. His time starts running out fast when he's diagnosed with terminal lung cancer. And as the saying goes, all hell starts breaking loose.

A beautiful detective (Rachel Weisz) with latent psychic abilities seeks the ultra-cynical occultist's help in the strange death of her twin sister. Demons are upsetting the cosmic balance by trying to break into the world; one demon comprised of bugs even attacks Constantine in public. And a Mexican peasant who's found the Spear of Destiny (which stabbed Jesus) is making his way toward L.A. trailing horror in his wake.

Looking for answers, Constantine rubs up against some cats who stand out even in L.A. The androgynous angel Gabriel (Tilda Swinton) isn't the least bit interested in helping him. Ex-witch doctor Midnite (Djimon Hounsou) owns an exclusive club that's neutral ground for the half-breeds. Suave-looking demon half-breed Balthazar (Bush musician Gavin Rossdale) can't wait for Constantine's demise. A scholar (Max Baker) who lives downstairs behind a bowling alley supplies him with holy water, dragon's breath and other accoutrements. And Constantine's young driver, Chaz (Shia LaBeouf), would do anything to become his apprentice.

Rachel Weisz

For all its darkness, the movie is so much more comic-booky than the adult-oriented "Hellblazer" comic that it's sometimes laughable in the wrong places. Constantine whups demons with a cross-shaped shotgun and delivers haymakers with holy knuckle-dusters. And it's a howler when white-suited Satan (Peter Stormare) teases him with the light for his last smoke. Apparently Paul Lynde wasn't available.

The quintessentially English and blond character Constantine (originally modeled after Sting) has been around nearly two decades, and making him a Yank is characteristic of DC/Warner's clueless arrogance with good source material. (Still licking your wounds from "Catwoman"? Remember "The League of Extraordinary Gentlemen" — also from the mind of Constantine's abused creator, Alan Moore?) There's a reason why Marvel's track record on film is better. (Not that "Elektra" builds Marvel's case.)

Director Francis Lawrence comes from music videos — a pedigree that never inspires much storytelling confidence — and he fills "Constantine" with fantastic images. For instance, cattle fall dead as the possessed spear guy walks through them. And hell is a doozy.

Which raises another point: In its own demon-ass-kicking way, "Constantine's" visions of heaven and hell — and what lands you in either place — make it the most staunchly Christian film since "Left Behind." Except it's entertaining.

Mark Rahner: 206-464-8259 or mrahner@seattletimes.com