Scene 1 - After a brief orchestral Introducción, the curtain rises to reveal a Madrid street. It is pouring with rain, and the soaked crowd of madrileños sing a popular rhyme about the tiresome inevitability of the wet weather (Coro: "Que llueva, que llueva".)
Scene 2 - A flooded quarter of Madrid. The crowd hail 1889, hoping that he will be drier than his older brother, and that the municipal authorities will manage him rather better. The familiar figure of Neptune appears in his impressive chariot, escaped from his stone fountain near the Prado Museum and wearing a fashionable brown suit. To an infectious waltz tune he glories in the new freedom available to him in the flooded streets, though the crowd reflects that there are some dangerous fish in Madrid who would scare even the Ruler of the Waves (Vals de Neptuno: "De los mares rey me llaman".)
1889 and Neptune are joined, in a dialogue heavy with contemporary social and political satire, by allegorical representatives of various leading newspapers. Eventually Neptune agrees to solve all their problems at a dance he will give that night for the Ministers of the Crown. A procession arrives from the bullring, singing a joyous Pasacalle in praise of the various quarters of the city (Coro: "¡Aquí viene la flor de Maravillas!") The crowd is joined by a Madrileño gentleman, and La Menegilda (servant girl) from La Gran Vía. In a sensuous Habanera she tells Neptune and his friends how the different quarters of Madrid contributed to the development of her dubious career, which has culminated in the post of mistress to a pallid, rich Englishman (Habanera: "Oiga usté, caballero".)
A gondola floats on, in which are seated the lead tenor and soprano from Carrión and Chapí's La bruja. They throw off their costumes and are revealed as allegorical representations of an Emigrant and the Republic respectively. In a delectable parody of Carrión's verse, the couple regret their need for parting, watched by a chorus of constables and the Inquisitor from the 1887 zarzuela (Zortzico: "¡Ay, niña de mis ojos!"). The Inquisitor bewails the threat that Emigration brings to the Republic, and exhorts the constables to catch and imprison the felon in a lugubrious Chotis: "¡Ay de mi! Qué cruel situación!". Eventually the Emigrant and The Republic float off happily together in their gondola, to the despair of the cleric and constabulary.
Scenes 3 & 4 - At the Liceo Ríus, three Municipal Guards bewail the fact their policemen's lot is not a happy one (Polka: "¡Traemos los cuerpos trunzaus!";) and a chulo and chula - Madrid teenagers - indulge in a love scene exposing the intellectual poverty of the city. A final tableau presents a decorative frieze extolling the successful Universal Exposition of Barcelona in 1888, as all hail Neptune and the New Year 1889 in a final grand apotheosis.