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.

"When you see this sign - run... run... run for your life!"

Credits

Cyril FrankelDirector

Stewart GrangerSuperintendent Cooper Smith

Susan HampshireTrudy Emberday

Cathleen NesbittLivia Emberday

James CullifordLuke Emberday