Bizarre nightmares plague Regan MacNeil four years after her possession and exorcism. Has the demon returned? And if so, can the combined faith and knowledge of a Vatican investigator and a hypnotic research specialist free her from its grasp?

12-year-old Regan MacNeil begins to adapt an explicit new personality as strange events befall the local area of Georgetown. Her mother becomes torn between science and superstition in a desperate bid to save her daughter, and ultimately turns to her last hope: Father Damien Karras, a troubled priest who is struggling with his own faith.

This movie is a stark portrayal of life among a group of heroin addicts who hang out in Needle Park in New York City. Played against this setting is a low-key love story between Bobby, a young addict and small-time hustler, and Helen, a homeless girl who finds in her relationship with Bobby the stability she craves.