When a young boy is taken over by a malevolent spirit, John must put aside his misgivings over exorcising a child and convince the parents that their boy is not all that he seems.

While in art class, Zed has a bizarre vision of snakes that lead her and John to a small town where a preacher has mysteriously gained the ability to heal his congregation.

Anne Marie, a member of the Newcastle crew, asks John and Chas for help in Mexico City -- bringing them close to the heart of the rising darkness; Zed is haunted by her past.

John summons a demon into himself to help fend off an attack; Chas, Zed, and Anne Marie rush to save John.

When thousands of people in Brooklyn - including Chas' daughter - slip into comas, John must locate and defeat the evil forces responsible.

John is sent to help an old friend at Ivy University, where students have figured out how to get to an alternate dimension - only to be met by a killer.

John asks Manny to help him investigate a mysterious attack at a hospital; a health issue prompts Zed to question her visions.

John and Zed return to New Orleans when Detective Jim Corrigan asks for their help in the case of a missing girl. Papa Midnite takes steps toward exacting his revenge on John. Meanwhile, the truth behind the Rising Darkness comes to light.