The game stars John Constantine, the main character from the movie Constantine and the comic book series, Hellblazer, as he learns that unholy animals are somehow crossing into the realm of the earth without care. He is then sent by his associate, Beeman, to investigate this problem. Along with his investigation, he meets up with Father Hennessy, who provides support, along with the Storm Crow spell.
The game starts out as John is called in to dispel a demon from a little girl’s body in a hotel. (Just like in the movie.) After the exorcism is completed, the girl wakes from her hypnosis, feeling better. The screen then cuts to Beeman’s office, where John is being informed about the weakened line between Hell and Earth by Beeman. John then steps into a puddle in the corner of the room, utters an incantation, and winds up in Hell.
John sees people being chased and attacked by demons and then sees them coming for him. He, depending on the player’s choice, uses his gun, the first part of the Witch’s Curse set, to slay these demons. He then starts searching around Hell for the first piece of the Holy Shotgun, while seeing the horrors of Hell with his own eyes. As he searches, more souls are attacked and more demons are seen fighting against John. At a dead-end, he finds the second gun for the Witch’s Curse set but is grabbed by a bird-like demon and flown through the skies of Hell. He is dropped and then is ambushed by a hoard of demons – just in front of the holding stall of the Holy Shotgun piece. He then uses the water ampoule he was carrying and gets out of Hell.
Now equipped with the Crucifier, John searches the rest of the storeroom, finding a grate that leads to the generator room. He shuts off the power and heads for the blocked area, which is filled with water. John utters the incantation and is sent to Hell.