Editing The Pirates of Penzance (section)

=== Act II ===
The Major-General sits in a ruined chapel on his estate, surrounded by his daughters. His conscience is tortured by the lie that he told the pirates, and the girls attempt to console him ("Oh dry the glist'ning tear"). The Sergeant of Police and his corps arrive to announce their readiness to arrest the pirates ("When the foeman bares his steel"). The girls loudly express their admiration of the police for facing likely slaughter by fierce and merciless foes. The police are unnerved by this and leave reluctantly.

[[File:1919paradox.jpg|left|thumb|250px|"Have mercy on us!"]]
Left alone, Frederic, who is to lead the police, reflects on his opportunity to atone for a life of piracy ("Now for the pirates' lair"), at which point he encounters Ruth and the Pirate King. They have realised that Frederic's apprenticeship was worded so as to bind him to them until his twenty-first ''birthday'' – and, because that birthday happens to be on 29 February (in a [[leap year]]), it means that [[Quibble (plot device)|technically]] only five birthdays have passed ("When you had left our pirate fold"), and he will not reach his twenty-first birthday until he is in his eighties. Frederic is convinced by this logic and agrees to rejoin the pirates. He then sees it as his duty to inform the Pirate King of the Major-General's deception. The outraged outlaw declares that the pirates' "revenge will be swift and terrible" ("Away, away, my heart's on fire").

Frederic meets Mabel ("All is prepared"), and she pleads with him to stay ("Stay Frederic, stay"), but he feels bound by his duty to the pirates until his 21st birthday – in 1940. They agree to be faithful to each other until then, though to Mabel "It seems so long" ("Oh, here is love, and here is truth"); Frederic departs. Mabel steels herself ("No, I'll be brave") and tells the police that they must go alone to face the pirates. The police muse that an outlaw might be just like any other man, and it is a shame to deprive him of "that liberty which is so dear to all" ("When a felon's not engaged in his employment"). The police hide on hearing the approach of the pirates ("A rollicking band of pirates we"), who have stolen onto the estate, intending to take revenge for the Major-General's lie ("With cat-like tread").

Just then, Major-General Stanley appears, sleepless with guilt, and the pirates also hide ("Hush, hush! not a word"), while the Major-General listens to the soothing breeze ("Sighing softly to the river"). The girls come looking for him. The pirates leap out to seize them, and the Pirate King urges the captured Major-General to prepare for death. The police rush to their defence but are easily defeated. The Sergeant has one stratagem left: he demands that the pirates yield "in [[Queen Victoria]]'s name"; the pirates, overcome with loyalty to their Queen, do so. Ruth appears and reveals that the pirates are "all noblemen who have gone wrong". The Major-General is impressed by this and all is forgiven. Frederic and Mabel are reunited, and the Major-General is happy to marry his daughters to the noble ex-pirates after all ("Poor Wand'ring Ones" (reprise)).