American professor John Holden arrives in London for a conference on parapsychology only to discover that the colleague he was supposed to meet was killed in a freak accident the day before. It turns out that the deceased had been investigating a cult lead by Dr. Julian Karswell. Though a skeptic, Holden is suspicious of the devil-worshiping Karswell. Following a trail of mysterious manuscripts, Holden enters a world that makes him question his faith in science.
Dana Andrews
Dr. John Holden
Peggy Cummins
Joanna Harrington
Niall MacGinnis
Dr. Julian Karswell
Maurice Denham
Professor Henry Harrington
Athene Seyler
Mrs. Karswell
Liam Redmond
Professor Mark O'Brien
Reginald Beckwith
Mr. Meek
Ewan Roberts
Lloyd Williamson
