Plot

A decade after a tragic mistake, Chas Chandler and occult investigator John Constantine set out to cure Chas's daughter, Trish, from a demonically induced coma.

A decade after a tragic mistake, Chas Chandler and occult investigator, John Constantine, set out to cure Chas's daughter, Trish, from a demonically induced coma. With the help of the mysterious Nightmare Nurse, the influential Queen of Angels, and the brutal Aztec God, Mictlantecuhtli, they just might have the chance to outsmart the demon Beroul and save Trish's soul.

John Constantine awakes from a dream of whispers from around the world. He finds himself in his apartment surrounded by miniature trench-cloaked projections of his inner demons. Constantine is battling his own inner demons who have somehow manifested in a physical form. They attack John, who then uses magic to absorb the demons back into his subconscious.

A decade after a tragic mistake, family man Chas (Damian O'Hare) meets occult investigator John Constantine (Matt Ryan). Chas asks John to help his daughter Trish, who has unexpectedly fallen into a coma, which Chas suspects to be the result of dark magic. John uses magic on Trish and discovers that her aura is tainted. Renne (Emily O'Brien) is Chas' wife who is now separated.

With the help of the mysterious Nightmare Nurse, the influential Queen of Angels, and brutal Aztec God Mictlantecuhtli (Rick D. Wasserman), the pair just might have a chance at outsmarting the demon Beroul (Jim Meskimen) to save Trish's soul.

Constantine summons to Nightmare Nurse to diagnose Trish. She tells him that Trish's body is not possessed by any demon. In fact, her essence is not in her body. The Nurse possesses Trish's body to figure out what happened to her. Trish is briefly able to communicate through Asa before a demonic entity takes over. Beroul has kidnapped Trish's soul & is hiding it in a cage inside his own heart. Beroul gives an LA address to Constantine for a rendezvous. In LA Constantine finds 23 cases of a "coma" bug. While Constantine is in LA, Nightmare Nurse stays behind to guard Trish's body.

Renee reveals that John and Chas had been best friends since they were kids and even formed a band together as young adults. They played at a nightclub owned by Alex Vogue, who was into the dark arts. When they found out that their mentor Alex Logue was using his daughter Astra to enact a dark spell below his Newcastle night club, John, having practiced occultism since he was a boy, attempted to save Astra by conjuring a real demon. The demon Nergal killed Alex and his followers, but Constantine never put a binding spell around it, so it attacked the nightclub and killed many people and took Astra away to Hell as the price for saving her. His trauma regarding the incident even lead him to be committed to a psychiatric institute, but Renee does not remember sharing this information with Asa.

John has a dream of the worldwide whispers again and suspects that someone is messing with his mind. Chas and Constantine reach the address, where Constantine finds Beroul. Beroul tells Constantine that he wants to start a Hell Franchise in LA. The demon explains that his soul-snatching scheme was just a ploy to enlist John's services. Beroul has 5 other demons who are competing against him. He wants Constantine to eliminate the other demons in exchange for Trish. The demon forces John to aid him by showing that he has Trish's soul trapped inside his body. Meanwhile the longer Trish's soul is away from her body, the more difficult it is for Nightmare Nurse to protect her. Beroul also reveals that he is Nergal.

In his quest, Constantine is helped many times by a mysterious entity, that never reveals its identity. Eventually she introduces herself as Queen of Angels. She is the collective consciousness of the city of LA, who had been following John ever since he arrived by possessing various people, including the driver that rescued him. Seducing him, she admits that she unleashed his inner demons as a test, and tells him that she will not allow demons of despair to poison a city of hope. Returning to Chas, John admits that he doesn't have the power to defeat Nergal's enemies on his own. He then hatches a plan.

For additional firepower Constantine summons brutal Aztec God Mictlantecuhtli (Rick D. Wasserman), who was once very powerful, but now hides in LA, feeding on carcass of the dead animals to regain his power. Constantine offers him 5 demon souls to feast on and leads him to the hiding place of Nergal's competitors. In the fight Mictlantecuhtli wins but is severely injured. Constantine kills him. Constantine then lures the demons to an unconsecrated church by promising to hand over Nergal, traps them inside with holy water, and allows the god and demons to fight each other, then finishes off the victorious god with a spell.

Constantine goes back to Nergal to free Trish, only to realize that the Queen was working with Nergal all this while. Queen made a deal with Nergal for him to take a few souls from the city every year in exchange for the city's survival.

Constantine hits rock bottom. He makes a plan to lure Nergal out of his lair. Returning to the hospital, John summons Nergal. He attempts a bluff: cutting Nergal off from his wards, harassing him with the inner Constantine demons, and opening all of the gates between Hell and Los Angeles, leaving Nergal with 5000 competitors to face instead of 5. Nergal calls John's bluff, forcing him to use his fallback plan: the Camdever Curse.

Constantine makes a connection of Chas with Trish (through Nergal) and the same connection between Renne and Trish via the Nightmare Nurse. He surges their love for Trish into Nergal, which is like cancer to him. Nergal explodes and dies, and Trish's soul is released.

Once Nergal is defeated, at a diner, John reveals to Chas that love was the sacrifice that powered the curse: Trish and Renee will never again remember Chas, and, further, Chas will not remember John. Angela appears in the form of an old man, thanks John, and promises to take care of Chas. John heads off to return to London, with one surviving inner demon to keep him company.