In Chicago, Illinois a woman enters a creepy abandoned recording studio.
She removes a panel from the wall and retrieves a bible. Inside the book, there's a vinyl record which she takes to a producer friend to be analyzed. Though she warns the man not to listen to it, he does and an evil force takes control causing him to kill himself.
Constantine learns of this tragic loss, and it's personal as the music producer had worked with his band Mucus Membrane on their only record.
John and Zed travel to Chicago and locate the man's corpse at the morgue. Using the "hand of glory" and an incantation John briefly communes with the dead man. When John asks "who did this to you?" the corpse replies... "the voice" "acetate" and "moonrise."
Using Google, Zed figures out that "Moonrise" was an old blues record label in the 1930's. The owner is still alive, so they decide to pay him a visit.
The old man shares the story of Willie Cole. Legend had it Willie had sold his soul to the devil. While recording at Moonrise Studios one night the devil came to collect his prize. The acetate was running and captured the deceivers voice. Marcus claims that the tried to destroy the thing, but nothing worked so he sealed it up inside that wall at the old studio.
When a private investigator recently appeared asking about the acetate, the old man noticed the name, Fell, on the check used to pay him.
Ian Fell was a metal head also discovered by Bernie. Zed assumes he probably sold his soul to the devil as well. However, when John confronts Fell it's revealed that the musician's wife, Jasmine, is the one responsible. This wasn't about fame though, her husband was dying of cancer and she wasn't prepared to lose him. At the hospital a "soul broker" offered her a deal and Ian soon went into remission.
Jasmine tells John the man then offered to trade her soul back for the acetate. She had a text with his address on her phone.
John goes to the location but quickly realizes that Papa Midnite, a voodoo priest, is the one behind all this. He tells John the acetate is his insurance policy.
Unfortunately, John is knocked out by Midnite's goons who later arrive at the Fell mansion looking for the acetate. The artifact calls out to them and they touch it. The duo is soon wreaking havoc all over town.
Zed locates and saves John's life again. They track the acetate to a local radio station, it wants to be heard.
Wearing headphones and blasting music John attempts to stop Midnite's men. Unfortunately, John's headphones fall off and the artifact's power takes him over.
Papa Midnite, still chasing the artifact, arrives and destroys the speakers in the room. He's there to claim his prize but John refuses to let him have it.
Drawing on the discs own dark magic via an incantation, he manages to send the artifact back to hell.
Jasmine's soul is saved when John forces Anton to literally eat his own contract.
Constantine's made an enemy of Papa Midnite though who burns a voodoo doll likeness of John.