In the 1850s, Frederic, David Hobson, is placed in the care of his nursemaid Ruth, Suzanne Johnson, to be apprenticed to a pilot. But Ruth, who is hard of hearing, mishears the instructions and instead binds him to the Pirate King, Anthony Warlow. Now turning 21, his service is finished, and he resolves to abandon piracy and live a blameless life, driven by a steadfast sense of duty.
Ruth hopes to accompany him on his new path, but just then he encounters a group of young maidens, among them Mabel, Taryn Fiebig, who is the daughter of Major-General Stanley, John Bolton-Wood. Frederic is surprised to find that Ruth’s view of him as a “plain and old” caregiver is at odds with the excitement of companionship and romance. Mabel offers him a chance at redemption through love, and Frederic accepts.
Soon after, the pirates return, seize the young ladies, and plan to marry them off. The Major-General Stanley arrives and lies to the pirates, claiming he is an orphan—an attempt to protect his daughters and themselves. The pirates, who themselves are orphans, decide not to attack another orphan, and they let him and his daughters go free.
Later, General Stanley wrestles with his conscience, having told a falsehood, while Mabel and Frederic try to buoy his spirits. Frederic enlists the constabulary to help him confront the pirate threat. The Police arrive, but they are cowardly and hesitant. As the situation unfolds, the Pirate King and Ruth discover a crucial detail: Frederic’s apprenticeship indenture contains a loophole tied to his leap-year birth on February 29, which means he remains bound to the pirates until his 21st birthday in 1940. Mabel vows to wait for him until then.
The Police return and hide as the pirates close in on the Major-General. The pirates seize the guilt-ridden General, and a tense confrontation ensues. Mabel encourages the police to stand and fight, but the pirates are momentarily overpowering. Then the Sergeant of Police, Richard Alexander, steps forward and calls on the pirates to yield in Queen Victoria's name:
> yield in Queen Victoria's name
Moved by his appeal and the sense of duty that permeates the scene, the pirates yield, tearfully surrendering to the police, and release the Major-General. Ruth reveals a truth about the pirates—that they are noblemen who have gone astray. The Major-General pardons them and invites them to resume their parliamentary ranks and to marry his daughters. With forgiveness granted and romance unresolved for the moment, the story closes on a hopeful note, and the ensemble celebrates a happy ending.
