This book is based on the same case as The Exorcist playing in theaters in 1973, which was based on William Blatty's 1971 book of the same title. The movie was fictionalized; this book is what really happened. The author presents the information from various sources to reconstruct what happened to "Robbie Mannheim" in 1949. Several priests became convinced that he was a victim of demonic possession and began the exorcism rites for him. Many seemingly supernatural things happened before and during the exorcism. This book tells all. The diary from one of the priests involved is printed in the back of the book - but the story itself is so heavily drawn from the diary that reading it is rather repetitive. A careful reader may notice a difference in emphasis on various parts of the story, but there is no real departure from the diary itself. Possessed was first published in 1993, 44 years after the case actually happened.
This is a challenging book to read if you have any question at all about whether demonic possession could be real. The author himself questions the possession in his afterword. The beginning is a bit slow, but once all the background information has been established, the action picks up considerably. Readers who saw the original movie, or the Showtime movie Possessed will certainly enjoy this book. Anyone who has questioned Christianity or the existence of demons will also appreciate the straight-forward presentation and ability to make up their own mind after the evidence is presented.