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
as Dr. John Holden
Peggy Cummins
as Joanna Harrington
Niall MacGinnis
as Dr. Julian Karswell
Maurice Denham
as Professor Henry Harrington
Athene Seyler
as Mrs. Karswell
Liam Redmond
as Professor Mark O'Brien
Reginald Beckwith
as Mr. Meek
Ewan Roberts
as Lloyd Williamson
Peter Elliott
as Professor K.T. Kumar
Rosamund Greenwood
as Mrs. Meek
Brian Wilde
as Rand Hobart
Richard Leech
as Inspector Mottrarn
