"What if I told you that God and the devil made a wager,
a kind of standing bet for the souls of all mankind?" - John Constantine

Imagine that life on earth exists in a state of détente, a balance between the forces of good and evil scrupulously maintained through the ages. Humans choose their own paths in this realm and, in doing so, seal their fates for the realm beyond; some bound for heaven and some for hell.

As part of this divine wager for all the souls in the world, both God and the devil are restricted from direct contact with the human race and its free will but are allowed a measure of influence through intermediaries. Neither fully angels nor demons, these earthbound influence peddlers are best described as half-breeds. "Suppose you were very good in life, or very bad. They wrap your soul up in human skin and send you back on missions," explains John Constantine, a man who has literally been to hell and back.

In ordinary bodies these half-breeds slip freely through the human population, doing their work. They share the roads, hold jobs, engage in myriad relationships with their human hosts and no one is the wiser. "They look just like us," says Constantine director Francis Lawrence. "You could live side by side with them, maybe even be married to one of them or be friends with them and never know it."

But John Constantine can see them.

Since childhood, he's had the unique ability - he would call it a curse - to recognize these beings for what they truly are beneath their fragile tissue of disguise. He sees their true faces, either beatific or demonic. Driven to suicide, in his youth, by this terrifying burden that no one understood, Constantine hoped for the peace it would bring but got instead a 2-minute tour of the depths of hell, a nightmare beyond imagination, before being resuscitated and snapped back into life.

Since that moment, he's known the hellish fate that awaits him when his life on earth is ended, and has been trying desperately to change it. Finding the traditional path to salvation closed to him, he resolves to earn entrance to heaven by waging war on the demon half-breeds on earth. An expert in demonology and black magic as well as an accomplished con man when he wants to be, Constantine uses sacred relics as weapons, along with his wits, his fists and anything else at his disposal to send countless hordes back to the underworld in shreds.

But he is an unlikely hero. Spurred not by any benevolent intention, he battles evil only to buy his way into a heaven that is closed to him, and grows increasingly cynical as these efforts have no effect.

Constantine's strange circumstances and embittered attitude are part of what attracted Keanu Reeves to the story and its title role. "It is one of the best scripts I've read," he says. "It has humor, intelligence, vitality, and I especially appreciated how everything was not obvious. There's mystery and contradiction. Constantine himself has a strong sense of morality yet his ethics are a little blurry. He's trying to right some wrongs but he doesn't always go about it in the nicest way. He's an anti-hero I've never seen before."

Constantly tormenting the renegade exorcist are half-breed entities from both sides. The angelic Gabriel, God's gatekeeper on Earth, continually denies Constantine the salvation he so fervently pursues. Unmoved by Constantine's private war and aware of his selfish motives, Gabriel admonishes repeatedly - and none too sympathetically - that he cannot buy his way into heaven, while Satan's emissary Balthazar mocks his futile efforts and reminds him his days are numbered. Hearing of Constantine's recently diagnosed terminal lung cancer, Balthazar is beside himself with malevolent glee.

Among Constantine's few allies is Chaz, his faithful driver and wannabe apprentice. Fascinated by what he sees of Constantine's world, albeit from a safe distance, Chaz makes up for his lack of practical experience with an encyclopedic knowledge of the religious and paranormal, in avid preparation for the day when Constantine might finally ask for his help. Constantine's former comrade, Midnite could be the source of more formidable help if Constantine hadn't all but burned that bridge. Once a faith healer and witch doctor, Midnite claims neutrality and offers his nightclub as a sanctuary for half-breeds from both sides while keeping his true loyalties to himself. Now he warns Constantine to respect the balance.

Still he persists. It's the only thing he can do. It has become his life.

Called to the site of another demonic possession by his old friend Father Hennessy, a weary priest whose body and soul have seen better days, he prepares for yet another exorcism. This time it's a young girl in the grip of the underworld, the latest in a series of countless exorcisms that Constantine has performed and yet this one suddenly feels different to him. With disbelief and then increasing alarm Constantine realizes that the demon inside this particular child is fighting not for possession of her tiny body but for a way to break through it and enter the physical world, a blatant breach of the age-old balance. This cannot be happening.

But that's just the first of several disturbing portents. En route home on the dark streets of downtown Los Angeles, Constantine is attacked by a demon - not a half-breed but a full-fledged demon, brazenly appearing on the earthly plane as if it had the right.

Later, as he sits alone pondering these inexplicable and terrifying incidents he is approached by Angela Dodson, a police detective with her own desperate questions about her sister Isabel's mysterious suicide. Raised to believe suicide is a mortal sin, Angela cannot accept that her sister would take her own life, even though surveillance footage from the psychiatric hospital where Isabel was a patient shows her leaping from the roof. Based on rumors Angela has heard about Constantine, linking him to strange and supernatural events in the city, she seeks him out against her skepticism, in hopes that he might help explain what really happened to Isabel.

But Constantine isn't the least bit interested in helping her. As Reeves explains, "He has problems of his own. He's just been diagnosed with terminal lung cancer. He knows he'll be landing in hell because of the life he took. His own. He's busy looking for a way out."
Consumed by his own concerns, Constantine at first turns her away… until he sees the hell-born entity stalking Angela as she walks away. He doesn't know how, or why, but somehow Angela is a key to the bizarre demonic activity that is swirling around them both.

One thing he knows for sure: the balance is breaking down. Something big is brewing.