On the quarter deck of the H.M.S. Pinafore sailors are discovered at work cleaning brass-work, splicing rope and singing as they work. Presently their work is interrupted by the arrival of a Portsmouth bumboat woman, nicknamed Little Buttercup. Her basket is crammed with tempting wares--snuff, tobacco, scissors, watches, knives and ribbons and laces for wives and sweethearts. She introduces herself in a charming little ditty:
- "I'm called little Buttercup,
- Dear little Buttercup
- Though I could never tell why."
In spite of Buttercup's gay and frivolous exterior she confesses to a canker-worm of worry that is eating its way into her heart. The secret of her remorse, which provides thedénouement of the plot, is not unconnected with the name of Ralph Rackstraw. Young Ralph, "the smartest lad in all the Fleet", and an A.B. of H.M.S. Pinafore, has fallen in love with Josephine, daughter of his captain. But Josephine is sought in marriage by no less a celebrity than Sir Joseph Porter, K.C.B., First Lord of the Admiralty. Ralph's love is returned by Josephine and to her father's dismay she confesses her love for Ralph, adding that though she can esteem, reverence and venerate Sir Joseph she cannot under any circumstances love him. "I hate myself when I think of the depth to which I have stooped in permitting myself to think tenderly of one so ignobly born--but I love him! I love him! I love him!" she cries and bursts into tears.
A barge is now seen to be approaching H.M.S. Pinafore and from it steps Sir Joseph Porter, accompanied by a collection of ladies, consisting of his sisters, his cousins and his aunts. Sir Joseph introduces himself in an impressive song:
- "When I was a boy, I served a term
- As office boy to an attourney's firm."
After this beginning Sir Joseph has risen to the position of First Lord of the Admiralty--a "take-off" by Gilbert of the newly-appointed First Sea Lord, William H. Smith, who, despite his lack of familiarity with the ocean, made a highly successful head of the Royal Navy. Sir Joseph inspects the crew of H.M.S. Pinafore and in a democratic speech declares that all men are equal. These sentiments encourage Ralph Rackstraw to propose to Josephine, who, however, temporizes and rebukes him for raising his eyes to the daughter of his commanding officer: "Sir, you forget the disparity of our ranks." In despair, Ralph decides to take his life, and has actually put the pistol to his head when Josephine intervenes. "Ah! stay your hand. I love you!" she tells him, making her confession before the whole ship's company. They plan to elope that very night, in spite of objections from Ralph's odious mess-mate, Dick Deadeye. Twisted in mind and body, he urges Ralph vindictively to "remember she's your gallant Captain's daughter and you the meanest slave that crawls the water". But he is howled down by the rest of the crew, who all side with Ralph and Josephine.
That night on board H.M.S. Pinafore Sir Joseph expresses to Captain Corcoran his disappointment with Josephine, who has not responded favourably to his proposals of marriage. "Josephine is of course sensible of your condescension, Sir Joseph, but perhaps your exalted rank dazzles her," pleads the Captain. So Sir Joseph once again tackles Josephine, and hoping to further his own suit, he tells her that in his opinion difference of social status is no barrier to love. Little does he know how eloquently he has pleaded his rival's cause, and Josephine, who was in doubt as to the propriety of eloping with Ralph, has now no qualms. But Dick Deadeye has warned Captain Corcoran of the intended elopement and the Captain is in time to prevent it. He rebukes Josephine for the company she keeps, and Ralph Rackstraw bitterly resents the Captain's class-consciousness, telling him proudly: "I am an Englishman." The crew back him up and the boatswain sings in his support:
- "For he himself has said it
- And it's greatly to his credit
- That he is an English man.
- (That he is an English man.)"
But Captain Corcoran is unable to repress his anger, and in front of all Sir Joseph's female relations, who have arrived on the scene, he turns on Ralph with: "Damme, it's too bad!" Sir Joseph is horrified at the Captain's bad language, and orders him to his cabin in disgrace; then, turning to Ralph Rackstraw, he inquires in fatherly fashion how Captain Corcoran came to forget himself. "I am quite sure you had given him no cause for annoyance." Ralph then admits his love for Josephine, who precipitates herself into his arms. Sir Joseph is livid with rage. "Insolent sailor, you shall repent this outrage. Seize him," he commands. And Ralph is led off in custody. "Josephine, I cannot tell you the distress I feel at this most painful revelation. You, whom I honoured by seeking in marriage--you, the daughter of a Captain in the Royal Navy," says the injured First Sea Lord.
At this point Little Buttercup intervenes with a truly remarkable story. Many years before she had been a baby-farmer and in her charge were two infants; one a well-born babe, the other of humble origin. Inadvertently she had mixed them up, and Ralph Rackstraw is really named Corcoran and the Captain is Ralph Rackstraw. On hearing this revelation Sir Joseph sends for the two affected parties, and Ralph enters dressed in Captain's uniform, and Captain Corcoran as a common sailor. Addressing Captain Corcoran, Sir Joseph says: "I need not tell you that after this change in your condition my marriage with your daughter is out of the question." The Captain protests in Sir Joseph's own words that "Love levels all ranks." "It does to a considerable extent, but it does not level them as much as that," says the First Sea Lord crushingly. Handing Josephine to Ralph, Sir Joseph admonishes him to treat her kindly, and the curtain falls on general rejoicing and a finale in which all the best tunes are repeated and which finishes on a patriotic note in praise of Englishmen.