The demon uses Nikki to hypnotise Andy, as Marcus and Tomas fight to save his soul.
The Exorcist – Season 2, Episode 7: “Help Me”

The demon uses Nikki to hypnotise Andy, as Marcus and Tomas fight to save his soul.
Marcus gets to know Peter better, and the island. Andy faces reality. Tomas investigates the foster home.
The priests get to the island, where disturbing things are happening under Andy's roof.
Marcus and Tomas encounter a new possession, or perhaps a hoax. Andy experiences a strange event.
Fathers Tomas and Marcus battle the demon in Cindy. In Washington, Andy figures out more about the kids under his care.
With Kyle and his father Simon together again, the beacons are faced with the new step in their journey: seal the darkness, or face the consequences.
Kyle discovers his daughter Amber is of great significance to the Great Merge; as is Megan, for disturbing reasons.
An old face returns to Rome, and suddenly Sarah Barnes is missing from the hospital. Meanwhile, Sidney's left at the hands of Rev. Anderson.
Kyle & Allison take their daughter Amber on the run from the demons, as Reverend Anderson brings Megan to the Lighthouse.
After Kyle grapples with the powerful force inside Chief Giles, he dies on the ER's operating table & goes to another place.
When Kyle & Giles go to find Sidney, at the request of Mayor Boyd, they find only new horrors.
Kyle uncovers more about his father, & Reverend Anderson comes face to face with Aaron after all this time.