Nine years ago Richard Allen fled England when his avaricious father, the Earl of Manford, betrothed him to Julia Miller, the young daughter of London's wealthiest merchant. Having seen how his father's ambition ruined his older brother's prospects for happiness with an arranged marriage, free-spirited Richard takes to the sea determined to live his own life. In the Caribbean, he joins a band of treasure-hunting pirates and adopts the persona of a Frenchman named Jean Paul. When he dares to slip back into England to carry out an urgent task for his captain, Richard falls in love with a married woman, Georgina Malory. Despite Georgina's indifference to him and her husband James Malory's threats to harm him, Richard is smitten. His next attempt to woo Georgina at a masked ball turns out to be a terrible mistake because it brings him face to face with another beautiful woman.

Grown-up and sophisticated, Julia Miller, a friend of Georgina's, is charmed by the masked Frenchman Jean Paul until she discovers he's really her detested fiancé! Julia has hired solicitors to have Richard declared dead so she can free herself from their betrothal and move on with her life. But when the Earl of Manford learns his son has returned and can fulfill the marriage contract, he sets in motion a chain of events that places Julia on the high seas with her fiancé who is not merely an irresponsible nobleman but a seductive, adventure-loving pirate!