American tourists David and Jack are savaged by an unidentified vicious animal whilst hiking on the Yorkshire Moors. Retiring to the home of a beautiful nurse to recuperate, David soon experiences disturbing changes to his mind and body.
When two mysterious deaths mar an otherwise pleasant weekend in the English countryside, unflappable flapper Lady Eileen Brent teams up with the dashing Jimmy Thesinger to solve the dastardly deeds. Their sleuthing leads them into a world of espionage and international intrigue as they discover a secret society known as "The Seven Dials" and the attempted theft of top-secret government documents.
A millionaire leaves his fortune to an unknown woman, Catherine Durell, who travels to Norway to take over her newly inherited property. Soon, she finds herself caught in a maelstrom of murder and terror.