A Scotland Yard detective is investigating a string of robberies and a murder, and the information he uncovers leads him to the estate of a wealthy but strange English family, who share their mansion with a group of nuns. The detective comes to suspect that neither the family nor the nuns is quite what they seem to be.

• Portman Productions
• Rialto Film
• Stewart Granger
• Susan Hampshire
• Cathleen Nesbitt
• James Culliford
• Brigitte Horney
• Robert Morley
• Sophie Hardy
• Colin Gordon