In 17th century France a group of nuns described some unsettling visitations at their convent, which developed into a story of possession, political intrigue, and a moment in time that was rife with social tensions.
Research:

Behind the Scenes Minis: Piece of Work
17:48

E. Virgil Neal: Hypnotist, Fraudster, Tycoon, Part 2
41:22

E. Virgil Neal: Hypnotist, Fraudster, Tycoon - Part 1
35:28