HMS Pinafore Plot Summary
H.M.S. Pinafore is in port at Portsmouth. It is noontime, and the sailors are on the quarterdeck, "cleaning brasswork, splicing rope, etc."
Little Buttercup, a Portsmouth "bumboat woman" (dockside vendor) — so-named because she is the "rosiest, roundest, and reddest beauty in all Spithead" — comes on board to sell her wares. She hints that she is hiding a dark secret. The Boatswain disbelieves her, but the villainous and ugly Dick Deadeye says he's often suspected something of the sort.
Ralph Rackstraw, "the smartest lad in all the fleet," enters, declaring his love for the Captain's daughter, Josephine. His fellow sailors (excepting Dick) offer their sympathies, but can give Ralph little hope that his love will ever be returned.
The Captain greets his crew and compliments them on their politeness, saying that he returns the compliment by never (well, hardly ever) using bad language, such as "a big, big D." After the sailors have left, the Captain complains to Little Buttercup that Josephine has not taken kindly to a marriage proposal from Sir Joseph Porter, the First Lord of the Admiralty. Buttercup says that she knows how it feels to love in vain. As she leaves, the Captain remarks that she is "a plump and pleasing person." Josephine enters and confesses to her father that she loves a common sailor, but she is a dutiful daughter and will marry Sir Joseph as her father wishes.
Sir Joseph comes on board, accompanied by his sisters, cousins, and aunts. After telling everyone how he came to be "ruler of the Queen's Navee," he delivers a lesson in etiquette. He tells the Captain that he must always say "if you please" after an order; for, as he says, "A British sailor is any man's equal – excepting mine." He has composed a song to illustrate that point, and he gives a copy of it to Ralph.
Elated by Sir Joseph's views on equality, Ralph decides that he will confess his love to Josephine. His shipmates approve heartily, except for Dick, who is forced to listen to Sir Joseph's song before the sailors exit, leaving Ralph alone. Josephine now enters, and Ralph confesses his love. Although she finds Sir Joseph's attentions nauseating, she knows she is obligated to marry him. Keeping her feelings to herself, she haughtily rejects Ralph's advances.
Ralph summons his shipmates, and tells them he is bent on suicide. He puts a pistol to his head, but as he is about to pull the trigger, Josephine enters, proclaiming she loves him after all. Ralph and Josephine plan to sneak ashore to get married that night. Dick Deadeye warns them that their actions will lead to trouble, but he is ignored by the joyous ensemble.
Later that night, under a full moon, Captain Corcoran confesses his concerns: all his friends are deserting him, and Sir Joseph has threatened a court-martial. Little Buttercup offers sympathy. He tells her that, if it were not for the difference in their social standing, he would have returned her affections. She prophecies that things are not all as they seem, and that a change is in store, but he does not understand her.
Sir Joseph enters, and complains that Josephine has not yet agreed to marry him. The Captain speculates that she is probably dazzled by his superior rank, and that if he can persuade her that "love levels all ranks," she will accept his proposal. When Sir Joseph makes this argument, a delighted Josephine says that she is convinced. The Captain and Sir Joseph rejoice, but Josephine, in an aside, admits that she is now more determined than ever to marry Ralph.
Dick Deadeye intercepts the Captain, and tells him of the lovers' plans to elope. The Captain confronts Ralph and Josephine as they try to leave the ship. The pair declare their love, adding that "I am (He is) an Englishman!" The furious Captain is unmoved, and says, "Why, damme, it's too bad!" Sir Joseph and his relatives, who have overheard, are shocked to hear swearing on board a ship, and Sir Joseph orders the Captain to his cabin.
When Sir Joseph asks what had provoked this outburst, Ralph replies that it was his declaration of love for Josephine. Furious once more at this revelation, Sir Joseph has Ralph put in chains and taken to the ship's dungeon. Little Buttercup now reveals her secret. Years before, when she was a nursemaid, she had cared for two babies, one "of low condition," the other "a regular patrician." She confesses that she "mixed those children up and not a creature knew it.... The wellborn babe was Ralph; your Captain was the other."
Sir Joseph now realizes that Ralph should have been the Captain, and the Captain should have been Ralph. He summons both, and they emerge wearing one another's uniforms: Ralph is now middle-class, and in command of the Pinafore, while the former Captain is now a common sailor. Sir Joseph's marriage with Josephine is now impossible. He gives her to now-Captain Rackstraw. The former Captain, with his rank reduced, is free to marry Buttercup. Sir Joseph settles for his cousin Hebe, and all ends in general rejoicing.