When Henry Scarlett's wife dies, he and his daughter Sylvia leave Marseilles to start a new life in England.  To help her debt-ridden father escape from his creditors, Sylvia cuts her hair and dresses as a young man, calling herself Sylvester.  Broke, Henry decides to smuggle some French lace through customs but makes the mistake of confessing his crime to Jimmy Monkley, a Cockney confidence man who exposes them to the customs authorities.  Monkley tells them later on the train that he turned them in to keep the police from finding the smuggled diamonds in his own shoe.

Impressed by Monkley's cleverness and the £100 he gives them as compensation, Henry and Sylvia agree to become partners with him, and in London, the trio attempts several unsuccessful con games.  After Monkley tries to trick Maudie Tilt, a rich woman's maid, into stealing her mistress' pearl necklace, Sylvia denounces him and insists that they pursue a more honest path.

Dressed in harlequin costumes, the trio and Maudie, with whom Henry falls in love, tour Cornwall as the "Pink Pierrots."  In one village, they meet Michael Fane, an aristocratic but bohemian artist, who asks the spunky Sylvia to pose for him.  Strongly attracted to Michael, Sylvia steals some women's clothing and shows up at his cottage as herself.  Although he is involved with the Russian aristocrat Lily, Michael flirts with the starry-eyed Sylvia, delighted by her unmasking.

Later, however, when the seductive Lily arrives, he all but dismisses Sylvia.  Heartbroken, Sylvia returns to the caravan, only to discover that her father has committed suicide because Maudie deserted him.  Soon after, Lily tries to drown herself but is saved by Monkley, who then runs off with her.  Michael and Sylvia chase after Lily and Monkley, convinced that they belong with them.  On the train, however, they realize that they actually love each other, and the pursuit ends.