Luke de Mountford is an heir to his uncle, Lord Radcliffe and he is preparing to marry beautiful Louise Harris. However, just when everything seems to be going well, another nephew with a claim to his uncle's fortune turns up unexpectedly. Luke is forced to reveal to Louise that their financial future may not be as guaranteed as he had hoped. When the intruder, Philip de Mountford, is discovered stabbed in a cab, suspicion naturally falls on Luke who certainly has a motive for murder.

Baroness Emmuska Orczy (1865-1947) was a Hungarian-born British novelist and playwright. She is best known for her series of novels featuring the Scarlet Pimpernel, the alter ego of Sir Percy Blakeney, a wealthy English fop who transforms into a formidable swordsman and a quick-thinking escape artist, establishing the "hero with a secret identity" into popular culture.