I've never read the Hellblazer comic, so fans looking to compare the two can move on.

Are they gone? Okay, let's talk about religion.

I suspect a lot of folks didn't like this movie because they didn't understand it. And the viewers who did understand it are probably offended by it. Appreciating the film requires a pretty good grasp of pop-theology and Roman Catholicism, a combination you don't find in many people besides gamers.

John Constantine (Keanu Reeves) is a former suicide that has been given another chance to walk amongst the living. Like most pulp heroes, John is a chain smoker. The twist here is that all the supposedly harmless smoking is a symbol of John's temptation by the vices of the flesh: as a result of his bad habit, he's dying from lung cancer.

Tragic, yes. But John knows for a fact he's going to hell. You see, Catholic doctrine dictates that those who commit suicide go to hell. This probably had to do a lot with the fact that martyrs in medieval times were torturing themselves in extremis until they died in twisted efforts to purify themselves. And really, religion doesn't work all that well without living worshippers. Thus the edict against suicide.

During John's brief experimentation with killing himself, he was in hell for two minutes. Two minutes is an eternity in hell, which looks like wherever you happen to be before you crossed over, only under the perpetual flames of a nuclear blast. Underneath all those flames and soot are the damned, gnawing and clawing each other. It's all very Dantean.

And yet John has been tasked with maintaining the balance, an eternal war beyond God's angels and the Devil's demons. Neither is allowed on this plane of existence, so half-breeds roam the Earth instead. Angels take the guise of humans (sans wings except for those who can see them) and demons possess people.

The Exorcist established that possessed people stick to the ceiling and have blue veins and bad teeth. John takes the roll of an exorcist, ensuring that the demons get too strong a foothold in our world. Except that one of them tries to "break out" of a possessed little girl, which is a violation of the Divine Order.

As an aside, the term "plane" was brought into popular culture through Michael Moorcock and his Elric series. The movie uses the term liberally and it's unlikely that anyone but gamers will get it.

The plot gets twisty from there. Angela Dodson (Rachel Weisz), a pretty cop, has been unknowingly gunning down demons-in-human-form and feeling pretty guilty about it. Turns out she's psychic. So is her twin, Isabel. And in order for the antichrist to return, he must be born through a psychic and ripped out of the womb by the Spear of Destiny. That'd be the spear that pierced Christ's side.

Whew, that's a lot to take in.

All this culminates in John having to work twice as hard as he realizes demons aren't just trying to get into our world, they're already here and killing off the good guys. After Angela's sister Isabel commits suicide to avoid becoming the antichrist's mother, Angela and John team up to try to stop the ensuing invasion.

It soon becomes clear that the lines of good and evil are not so clearly drawn: angels do wicked things and devils come to the rescue. Waitaminute, haven't we seen this before?

If it sounds familiar, it's because The Prophecy covered the same ground with the same characters: Gabriel, Lucifer, and a regular Joe who lost his faith in the middle. The acting was better. Lucifer was just plain creepy (played by Viggo Mortensen). And Gabriel was played by Christopher Walken, who just rocks on toast in everything he's in.

Instead, we get Peter Stormare, a Goodfellas version of Lucifer. Tilda Swinton plays Gabriel, whose chief attribute is being androgynous-looking (see the movie Orlando). There are other quirky characters playing one-dimensional comic book types (including Pruitt Taylor Vince as a psychic priest), but they're all there to support John and get killed so he's really, really pissed when he fights the main bad guy. And of course there's the 21st century Kevin Costner of our time, Keanu Reeves. Reeves' mumbling tested my patience and I missed out on a few important plot points because of it. But he's merely a canvas for a bigger movie and it's unfair to overly criticize the film when ultimately Constantine's supposed to be a shlub with a bad habit.

The director (Francis Lawrence) has fits of brilliance, including a scene where the holder of the Spear of Destiny walks down a road, causing a herd of cows to drop as he passes. Or Angela being sucked through wall after wall of a skyscraper, Forgotten-style, with John in hot pursuit. Or when John and Angela stand in front of a statue of the Virgin Mary to face off against hundreds of demons hovering in the darkness, just out of sight.

It's easy to dismiss the movie as Van Helsing with demons. Yes, there is a holy shotgun blowing up demons. Yes, they do bless the sprinkler system and turn it into holy water. So what? This is pulp noir, dark stuff in Los Angeles, the City of Angels. That Constantine dishes up a round of butt kicking along with its crazy theology only adds to the fun.