The Pirates of Penzance

Plot Act I: Frederic is seen celebrating his twenty-first anniversary in the company of a group of pirates. His nurse Ruth appears and reveals that she had apprenticed Fredric to the pirate band by mistake, many years ago ("When Frederic was a little lad"). Although Frederic is sympathetic to his pirate friends (they being all orphans whose gentle natures make their piratical careers difficult) he nonetheless resolves to leave the band. He invites the Pirate King to go with him, but is refused ("Oh! better far to live and die"). Frederic sees a group of beautiful young girls on the shore, and appeals to them for affection ("Oh! is there not one maiden breast") to help him reform; one of them, Mabel, responds to his plea ("Poor wandering one"). Frederic warns the girls of the pirates nearby, but they are interrupted by the arrival of said pirates, who wish to capture all the girls for wives. This plan is in turn interrupted by the arrival of the Major-General, the father of all the girls ("I am the very model of a modern Major-General"). On learning of the pirates' marital plans, he appeals to them for clemency on the grounds that he's an orphan. The soft-hearted pirates are sympathetic, and release the girls.

Act II: The Major-General sits in his family mausoleum, surrounded by his daughters. He laments his tortured conscience at the lie he told the Pirate King, while they attempt to console him ("Dear Father, why leave your bed?"). The Police Sergeant and his policemen enter to announce their readiness to go forth and arrest the pirates ("Tarantara"; "Go, ye heroes"). Frederic, who is to lead the group, pauses for a moment's reflection, at which point he encounters Ruth and the Pirate King. They inform him that his apprenticeship was worded so as to bind him to them until his twenty-first birthday - and, because that birthday happens to be on the extra day of Leap Year, that means that technically only five birthdays have passed ("A most ingenious paradox"). Frederic is convinced by this logic, and thus informs the Pirate King of the Major-General's lie.

After a farewell to Mabel ("Oh, leave me not to pine") the dutiful Frederic returns to fulfil his apprenticeship with the pirates. The police and their Sergeant are told they must go alone, and lament their fate ("When a Felon's not engaged in his employment"). They hide on hearing the approach of the pirates, who have stolen onto the grounds, meaning to avenge themselves for the Major-General's lie ("With cat-like tread"). The Major-General himself appears, insomniac with guilt, and his daughters follow him. The pirates, of course, leap to the attack, and the police to the defense; but the police are easily defeated. The Sergeant plays his trump card, demanding that the pirates yield "In Queen Victoria's name;" the pirates, overcome with patriotism, do so. Ruth appears to reveals that the orphan pirates are in fact noblemen; all is forgiven, Frederic and Mabel are reunited, and the Major-General is happy to marry his daughters to the noble pirates after all.