A ribald tangle of deceit among upper-class English households is revealed as Mirabell, a philanderer, cynically comforts Mrs. Fainall, his mistress. Mrs. Fainall is complaining that she completely detests her husband, and asks why Mirabell compelled her to marry him.
Observing that it is well to "have just so much disgust for your husband as may be sufficient to relish your lover," Mirabell reminds her: "If the familiarities of our loves had proved that consequence of which you were apprehensive, where could you have fixed a father's name with credit but on a husband?" As for his choice of Fainall, he says: "A better person ought not to have been sacrificed to the occasion; a worse had not answered the purpose."
Mrs. Fainall's passion for Mirabell, nevertheless, leads her to help him in his next scheme, even though it involves her own mother, Lady Wishfort, also infatuated with Mirabell. Mirabell wants to marry the beautiful and wealthy Mrs. Millamant, niece of Lady Wishfort, but her aunt--who is also her guardian--is jealously withholding her consent. With Mrs. Fainall's connivance, Mirabell arranges to have his servant, Waitwell, in the guise of an uncle called Sir Rowland, pay court to Lady Wishfort. Then, since he already has accomplished a secret marriage between Waitwell and Lady Wishfort's maid, Foible, he proposes to expose the scandal. His pride for silence is to be Mrs. Millamant and her fortune.
The scheme perfected, Foible tells Lady Wishfort that Sir Rowland has seen her picture and is infatuated by her loveliness. A meeting is arranged, but the plot is overheard by Mrs. Marwood, another of Mirabell's conquests and herself no mean schemer. Desiring Mirabell for herself, she promptly influences Lady Wishfort to agree that Mrs. Millamant shall be married to Sir Wilfull, a rich and amiable dunce. Then Mrs. Marwood, to make sure of success, enlists the help of Fainall who is infatuated with her and jealous of Mirabell. Fainall is a willing tool, complaining: "My wife is an arrant wife, and I am a cuckold....'Sdeath! To be out-witted, out-jilted, out-matrimoney'd!... 'Tis scurvy wedlock!"
Deceived by her caresses and angered by her reminder that Mirabell, his foe, may otherwise get Mrs. Millamant's fortune, Fainall agrees to Mrs. Marwood's plan: she will write a letter to be delivered to Lady Wishfort when Waitwell, as Sir Rowland, is with her. The letter will expose the fraud and Mirabell, she says, will be ruined. Mrs. Marwood neglects to tell Fainall of her scheme to save Mirabell for herself.
Lady Wishfort is a-twitter as she awaits the bogus Sir Rowland. She is informed by Foible that candles are ready, that the footmen are lined up in the hall in their best liveries, and that the coachman and postillion, well perfumed, are on hand for a good showing.
Assured by Foible that she looks "most killing well," Lady Wishfort ponders: "Well, and how shall I receive him?... Shall I sit? No, I won't sit--I'll walk--ay, I'll walk down from the door upon his entrance, and then turn full upon him--No, that will be too sudden. I'll lie--ay, I'll lie down--I'll receive him in my little dressing room--yes, yes, I'll give him the first impression on a couch. I won't lie neither, but loll and lean upon one elbow, with one foot a little dangling off, jogging in a thoughtful way--yes--and then as soon as he appears, start, ay, start and be surprised, and rise to meet him in a pretty disorder."
Sir Rowland arrives. He and Lady Wishfort get along famously at once, and Sir Rowland begs for an early marriage, declaring that his nephew, Mirabell, will poison him for his money if he learns of the romance. The jealous Lady Wishfort promptly agrees, suggesting that Sir Rowland starve Mirabell "gradually, inch by inch." Then Mrs. Marwood's letter, denouncing Sir Rowland as Waitwell, arrives, but Sir Rowland deftly declares the letter to be the work of his nephew, and he hies himself off "to fight him a duel."
Lady Wishfort learns of the deception that is being practiced, and turns on Foible: "Out of my house! To marry me to a serving-man! To make me the laughing-stock of the whole town! I'll have you locked up in Bridewell Jail, that's what I'll do!"
The frightened Foible confesses that it is Mirabell who has conceived the whole plot, and Lady Wishfort is planning a dire revenge when more trouble comes: Fainall, her son-in-law, demands that his wife turn over her whole fortune to him, else he and Mrs. Marwood will reveal to the world that Mrs. Fainall was Mirabell's mistress before her marriage and that she still is. Lady Wishfort is dazedly reflecting upon this new humiliation when Mirabell comes to her with another plan.
"If," he says, "a deep sense of the many injuries I have offered to so good a lady, with a sincere remorse and a hearty contrition, can but obtain the least glance of compassion, I am too happy.... Consider, madam, in reality it was an innocent device, though I confess it had a face of guiltiness. It was at most an artifice which love contrived--and errors which love produces have ever been accounted pardonable."
The susceptible Lady Wishfort offers to forgive Mirabell if he will renounce his idea of marrying Mrs. Millamant. Mirabell offers a compromise: if she will permit her niece to marry him, he will contrive to save Mrs. Fainall's reputation and fortune. If he can do this, Lady Wishfort agrees, she will forgive anything and consent to anything. Mirabell then tells her: "Well, then, as regards your daughter's reputation, she has nothing to fear from Fainall. For his own reputation is at stake. He and Mrs. Marwood--we have proof of it--have been and still are lovers.... And as regards your daughter's fortune, she need have no fear on that score, either: acting upon my advice, and relying upon my honesty, she has made me the trustee of her entire estate.
Cries Fainall: "'Tis outrageous!"
Says Mirabell: "'Tis the way of the world."
In a closing observation to the audience, he adds: