A distinguished English gentleman has a secret life--he is the notorious jewel thief the press has dubbed "The Amateur Cracksman". When he meets a woman and falls in love he decides to "retire" from that life, but an old friend comes to him with a predicament that entails him committing one last job.
18th century English aristocrat Sir Percy Blakeney leads a double life. He appears to be merely the effete aristocrat, but in reality is part of an underground effort to free French nobles from Robespierre's Reign of Terror.