Horror/thriller film about an occult detective and EXORCIST who journeys to Hell to battle Demons and confronts Lucifer. Directed by Francis Lawrence, the film stars Keanu Reeves as John Constantine and Rachel Weisz as Angela Dodson, a detective for the Los Angeles Police Department. The film is loosely based on characters in the comic book series Hellblazer, published by Vertigo Comics. In the movie, Constantine’s background is that he was born with the ability to detect Angels and Demons. Both beings are prohibited from interfering with the free will of humans, but half-breeds, humans mixed with either angels or Demons, can do so. Constantine is regarded by his parents as insane. He commits suicide and goes to hell but is restored to life by doctors. He grows up knowing that God and Satan are both angry with him, and because of his suicide attempt, he is eventually doomed to hell.
The film opens with a young man in Mexico who accidentally finds the Nazi Spear of Destiny and becomes possessed by a supernatural force. He goes to Los Angeles, leaving destruction in his wake. Meanwhile, Constantine, now a heavy chain smoker, has terminal lung cancer. He exorcizes a powerful Demon from a teenage girl. A mentally disturbed girl commits suicide in the hospital where Constantine is being treated. Her twin sister, Angela Dodson, goes to the hospital and encounters Constantine. A Catholic, she wants a church-sanctioned funeral for her sister, but the church refuses. Constantine seeks out an audience with the archangel Gabriel, a female entity, to ask why God does not forgive and heal him. Constantine sees that Demons are pursuing Angela, and he discovers that she, as he can, can detect angels and Demons. She has repressed this ability, and now he reawakens her to it. She takes him to meet Balthazar, a half-breed who is conspiring with the Demon MAMMON to conquer the Earth, a task he can do only with the help of the Spear of Destiny. Mammon takes Possession of Angela.
Constantine struggles in vain to exorcize Angela. Gabriel appears, bitter and disillusioned with humanity, and says she will release Mammon into the world. Constantine slashes his wrists, knowing that Lucifer will appear to collect his soul. When the Devil appears, time stops. Lucifer is enraged at Mammon’s plans and sends the Demon back to hell. He burns Gabriel’s wings and the angel is reduced to a human state.
Lucifer removes the cancer from Constantine’s lungs and abducts him to hell. Constantine is saved by Divine Light as a reward for his sacrifice of himself. He is returned to Earth and to Angela. The Spear of Destiny appears, and Gabriel taunts Constantine to kill her with it. Instead, he punches her in the face. Constantine gives the spear to Angela and quits smoking, now in command of his fate.