We meet John Constantine as he's going through electroshock therapy at a facility for the mentally deranged in Northern England. We learn he checked himself in voluntarily after witnessing the murder of a little girl by a demon.
The therapist doesn't buy the demon story and slightly mocks Constantine's business card which reads: John Constantine Exorcist, Demonologist and Master of the Dark Arts. He can handle her death he says, it her damnation that's eating him alive.
Though he's sworn off the supernatural, he comes across a possessed woman and exorcises the demon inside her. The words "LIV DIE" are written on the wall and he understands he's been wasting time at the asylum. He's got work to do.
In Atlanta, Liv Aberdine is getting ready to head home after work. She comes under attack in the parking lot, but Constantine pulls up in time to offer his assistance. He hands her his business card and enters a crater that opened in the ground.
An angel named Manny lands and informs Constantine that he was asked to watch over him. Manny tells Constantine that something dark is on the way.
Liv gets a ride home from the neighbor across the hall. She spots a man walking towards her and rushes inside her apartment. The man carves the eye of horus on her door for protection against the demon hunting her. The entity possesses her friend instead, and later makes another attempt on Liv's life.
Though she doesn't understand why this is happening to her Constantine explains her father was Jasper Winters, a master of the occult. He gives her a pendant that belonged to her father.
Liv begins seeing souls and Constantine tells her she's waking up. Seeing the world for what it really is. Just like her father could.
Constantine does some research and learns the name of the demon hunting Liv is Furcifer. He draws his strength from electricity. He has an idea how to stop Furcifer but it means using her as bait.
A security guard is paid off to allow Constantine and Liv up to the rooftop. There, Constantine draws a demon seal on the floor. When Furcifer comes for Liv it will enter the circle, the seal will hold it so Constantine can order it back to hell. He asks her to enter the circle.
The demon possesses the guard and faces off against Constantine on the rooftop. Furcifer steps into the demon seal and though he torments the demonologist, Constantine's incantation sends it back to hell.
Liv decides this is all too much for her and returns the pendant. She's made plans to move out to California. It was actually Constantine's plan to scare Liv away.
The episode ends with a mystery woman seen sketching dozens of images of Constantine. Who is she?