Scene 1 Hellena, a young woman about to enter a convent, questions her sister Florinda about whom she loves. Florinda admits she loves Belvile, an English colonel, but her father is determined that she marry the elderly Don Vincentio (who never actually appears in the play). Further complicating matters, Florinda's brother, Don Pedro, wants Florinda to marry his friend Don Antonio. Don Pedro enters with Stephano (his servant) and Callis (the sisters' governess). Pedro encourages Florinda to follow their father's wishes and marry Don Vincentio. Florinda refuses and Hellena supports her. This pleases Pedro, who says that he has a means for Florinda to escape that marriage... by marrying Don Antonio the very next day. Pedro exits and Florinda and Hellena convince Callis to let them disguise themselves and go to Carnival.
Scene 2 Three Englishmen, Belvile, Blunt, and Frederick, are walking in the town. Belvile is melancholic because Don Pedro has forbidden him to marry Florinda, favouring Antonio instead. Willmore, who has just arrived in Naples, enters and greets his friends. The Englishmen prepare for a night of love and feasting. Women dressed as courtesans enter and Willmore flirts with one of them, while Belvile snipes at him with references to venereal diseases.
Florinda, Hellena, and Valeria (their cousin) enter dressed like Gypsies, and promise to tell the men's fortunes. Willmore and Hellena flirt with one another; Hellena reveals she is destined to be a nun, to which Willmore replies “There’s no sinner like a young saint.” Hellena agrees to meet Willmore again later, presumably for a sexual liaison; he swears to love only her. Meanwhile, Lucetta, a "jilting wench," begins to seduce Blunt. Florinda reads Belvile's palm and begins to set up a meeting with him when she sees her brother approaching. She hastily gives him a letter and runs off with Hellena and Valeria. Pedro merely passes by.
Florinda's letter contains instructions for Belvile to come to her garden at ten that night and carry her off. Blunt sneaks off with Lucetta. The other men, who think of Blunt as a foolish provincial, realise that he has all their money with him, and hope that he does not come to harm. Frederick informs his friends of a new courtesan in Naples: Angellica Bianca, the former mistress of a dead Spanish general.
Scene 1 Willmore, Belvile, and Frederick are on their way to see Angellica when they come across Blunt. Blunt happily (and stupidly) says that Lucetta loves him and is waiting for him to join her later that night. The Englishmen laugh at him and retrieve their money, but leave Blunt “to be cozened” (cheated). Blunt objects to the accusation that Lucetta is a whore.
Angellica's servants hang up a portrait of her outside of her house. The Englishmen are astounded by her beauty but leave when they realise they do not have the money to buy her—one thousand crowns a month. Don Pedro enters and sees the picture and the price. He has the money and runs off to fetch it.
Angellica laments that no one has taken her up because of the high price, but when she learns of Don Pedro and Don Antonio, both of whom are rich, she decides to pursue them, then goes back inside. Pedro soon enters from one side of the stage, and Antonio enters from the other; both men are masked. Antonio is also struck by Angellica's portrait and wonders out loud if he could get away with sleeping with Angellica and still marry Florinda. At the mention of Florinda, Pedro recognises Antonio.
Angellica enters and bows to Antonio, who removes his mask and confirms his identity. Antonio tries to pay for Angellica, but Pedro steps up and declares that he was there first. They fight. Willmore and Blunt enter and break them up. Pedro challenges Antonio to a duel the next day over Angellica. Antonio accepts; Pedro exits.
Meanwhile, Willmore sees a smaller picture of Angellica and tries to steal it. Antonio tells him to put it back. Willmore refuses, saying that Antonio has the money to pay for the real thing. Angellica enters just in time to see another fight break out: soon all the Spaniards are fighting Willmore and Blunt. Belvile and Frederick enter and join their English comrades. Angellica asks Willmore to speak with her inside as she was initially very excited and impressed by him. Willmore goes, despite Belvile and Frederick's fears that Angellica is angry with him.
Scene 2 Willmore tries to persuade Angellica into sleeping with him for free as he was a seaman with not much cash and he was very much aware of the price that Angellica was charging. Normally Angellica would not agree to this, but she has fallen in love with Willmore, with his wits and his way and Willmore has described his love and temptation to get her forever (she has never loved anyone before). She agrees, despite her maidservant Moretta's warnings.
Scene 1 Florinda, Hellena, and Valeria enter, in different disguises. Hellena says she is not in love, but she cannot stop thinking about Willmore. The women see Belvile, Blunt, and Frederick approach, but the fact that Willmore is not with them leads the women to hide and eavesdrop on the men. Belvile, Blunt and Frederick have come to retrieve Willmore from Angellica, because he has been inside with her for two hours. Willmore comes out and brags about having enjoyed Angellica's charms for free. A servant of Lucetta's enters and takes Blunt back with him to Lucetta's lodgings.
Hellena, who has seen and heard everything Willmore said, comes out of hiding and pretends as if nothing has transpired. As Willmore begins to flirt with her again, Angellica enters, masked, and sees Willmore betraying the vows he made to her. Hellena finally reveals her face to Willmore, who praises her beauty. This is the last straw for Angellica. She orders one of her servants to find out who Hellena is and storms out. Hellena asks what Willmore was doing in Angellica's house; he denies that anything transpired. Hellena then attacks him, quoting to him what he had just said about Angellica. She makes Willmore promise never to see Angellica again.
Meanwhile, Florinda and Valeria are testing Belvile’s loyalty to Florinda by trying to seduce him while he doesn’t know who they are. He stands firm. The women exit, but Florinda leaves Belvile with a jewel (most likely a locket of some sort) so that he “may repent the opportunity you have lost by your modesty.” Belvile recognises Florinda’s picture in the locket and resolves to rescue her that night, with Willmore and Frederick's help.
Scene 2 Lucetta's house. Lucetta continues to seduce Blunt and goes into her bedroom to get undressed. Blunt follows her into the bedroom.
Scene 3 Blunt enters the bedroom and undresses to his shirt and drawers. Lucetta tells him to turn out the light. When the room is dark, the bed vanishes (with Lucetta) using a trapdoor system. Blunt stumbles around and then falls through another trapdoor. Lucetta, her servant, and her pimp enter and steal Blunt's money.
Scene 4 Blunt crawls out of a sewer, furious at having been tricked.
Scene 5 Florinda waits in her garden for Belvile wearing a nightgown. Willmore enters, drunk, mistakes Florinda for a prostitute, and tries to persuade her to sleep with him. When she resists he attempts to rape her. This is stopped by Belvile and Frederick entering. Florinda runs off. Willmore and Belvile almost fight, but Frederick intervenes. The noise however, brings Pedro and his servants to the garden. A fight breaks out and the English are driven off.
Scene 6 Willmore tries to explain to a furious Belvile that he didn’t know who Florinda was and mistook her for a whore. Belvile is still keen to fight. The men arrive outside Angellica’s house. Willmore nonchalantly says “I promised the kind baggage to lie with her tonight.” Belvile and Frederick leave to find Florinda.
Antonio enters, hoping that his page has paid Angellica so he can sleep with her. Willmore sees this and starts a fight with Antonio. Antonio falls, wounded; Willmore believes he has killed Antonio and runs off. Belvile runs in, fearing that it is Willmore who has been hurt. Soldiers enter and arrest Belvile, believing him to be the attacker. Antonio finds his strength and orders Belvile taken to his house.
Scene 1 Don Antonio does not believe that Belvile is innocent of having injured him; however, he offers Belvile an option other than imprisonment. Since Antonio is wounded, he cannot duel Pedro: Belvile must dress up as Antonio and go as him instead. Belvile agrees, believing that the fight must be over Florinda.
Scene 2 Florinda frets that Belvile did not come to her window as planned, and fears that the duel about to happen is between Belvile and Pedro. Pedro enters, masked, and reveals that he will be fighting Antonio, relieving some of Florinda's fears. Belvile enters, disguised as Antonio. Pedro accuses "Antonio" of having “the advantage of me in Angellica” and the men start to fight. Florinda runs in to stop them. Belvile is confused as to why Florinda would defend his rival but they push her away and fight. Florinda stops them again just as Belvile disarms Pedro. She begs him “by her you love” to spare Pedro. Belvile lays his sword at Florinda’s feet and swears his love to her. The action redeems him in Pedro’s eyes, so he gives his sister to the man he believes to be Antonio, demanding that they get married at once. Florinda protests, but Belvile secretly lifts his mask to show her who he is.
Just then, Willmore and Frederick enter. Wilmore greets him by embrace. The embrace makes Belvile drop his mask. Pedro now refuses to allow the wedding, since it was Antonio’s fight, not Belvile’s. He drags Florinda away, accusing her of trying to trick him. Belvile, furious at being thwarted yet again, turns on Willmore and chases him away.
Angellica enters with her servants Moretta and Sebastian, furious that Willmore loves Hellena. Sebastian runs after Willmore to bring him back. Angellica accuses Willmore of having another woman. Willmore, as usual, attempts to charm her back.
Hellena enters disguised as a man. She decides to interfere, approaching Angellica pretending to be one of Hellena's servants. She tells a story about a young girl who fell in love and was left standing at the altar because her lover came to Angellica. Then she reveals the lover to be Willmore. Angellica is moved by the story, Willmore is only excited and impatient to find out who the woman in question is. Suddenly, Willmore recognises Hellena and figures out what’s going on. He turns to Angellica and starts describing Hellena as a Gypsy, ugly, a monkey, etc. He tells Hellena to go back to her mistress and tell her “till she be handsome enough to be loved, or I dull enough to be religious, there will be small hopes of me.” Angellica is outraged with Willmore and vows to take revenge and sends Willmore away. Willmore exits with an aside in which he says he plans to try to win Hellena back.
Scene 3 Florinda and Valeria enter, disguised in different costumes, having momentarily escaped Pedro. Then Don Pedro, Belvile, and Willmore enter. Pedro and Belvile seem to be having a serious conversation. Willmore follows Florinda when she walks past, again thinking she is a courtesan.
Frederick comes in and relates Blunt's misadventures to Belvile and Pedro. They all go off to find him. Florinda reenters, still being chased by Willmore. Then Hellena arrives and sees Willmore pursuing this "unknown" woman. She sends a page to find out where they go.
Scene 4 Florinda ducks into a door to avoid Willmore; it turns out to be Belvile's house. The page Hellena sent goes off to relay the information.
Scene 5 Blunt is staying in Belvile's house. Florinda enters, sees Blunt and asks him for help. Blunt then attempts to rape her based on his new contempt for women (“be revenged on one whore for the sins of another”). Frederick enters, also convinced that Florinda is a prostitute, and joins Blunt. Florinda gives them a diamond ring and asks them to consult Belvile. Frederick fears that she might be a lady of some worth and asks Blunt to wait. Blunt is still sceptical but agrees. Frederick locks Florinda in a room.
Scene 1 Belvile, Willmore, Frederick, and Pedro break into Blunt's room and laugh at him. Blunt says that just a moment before there was a wench in his chamber and shows them the ring Florinda gave him. Belvile recognises the ring as the one he gave Florinda when they exchanged vows. The other men, unaware that the girl is Florinda, decide to let her out and have their way with her. They draw swords to see who has the longest. Don Pedro wins and unlocks Florinda's door.
Florinda runs in, still masked and pursued by Pedro. She is saved when Valeria arrives and persuades Pedro to leave by telling him that Callis knows where Florinda is hiding. Once he is gone, Florinda removes her mask. Valeria tells Belvile and Florinda to get married quickly, before Pedro returns. Frederick and Valeria decide to get married as well. Belvile sends a boy to fetch a priest. Frederick and Blunt realise that they almost raped Florinda and apologise, returning the ring. Florinda forgives them. Belvile, Florinda, Valeria, and Frederick exit to get married; Blunt goes off to see a tailor. Willmore stays behind to guard against Pedro's return.
Angellica enters, pointing a pistol at Willmore; she rages at him while threatening him with the gun. Willmore offers to pay her for her services; she refuses. As she prepares to kill him, Don Antonio enters with his arm in a sling. He takes the gun from Angellica, then recognises Willmore as the man who stole Angellica's picture. He offers to shoot Willmore. Pedro enters. Angellica decides to let Willmore live, and leaves. Don Pedro asks why Don Antonio missed the duel; Antonio tells him what happened, and leaves in a huff. Pedro decides to give Florinda to Belvile in revenge. Willmore informs him that the marriage has already occurred. Pedro exits.
Hellena enters, still in boy's clothes, and banters with Willmore, who wants to sleep with her but doesn't want to marry her. Hellena finally convinces him for marriage. Pedro, Belvile, Florinda, Frederick, and Valeria enter. They learn of Willmore and Hellena's engagement and Pedro approves, tired of fearing for his sister's honour (virginity). Blunt enters in a Spanish habit, looking ridiculous. Music plays and masquers from Carnival come in dancing. The play ends with vows of love between Hellena and Willmore.