The scene is Algernon Moncrieff’s flat in Half Moon Street, Piccadilly. The time is late afternoon, on what will eventually be identified as a Saturday. Lane the butler is making arrangements for tea. Algy refers to an entry in Lane’s butler’s book for “Thursday night,” when Lord Shoreham and Mr Worthing were dining with him, and questions the inordinate amount of champagne consumed by the servants. Lane explains that this is because the wine is of a first-rate brand, superior to what is served in married households. Ernest Worthing arrives. Algy asks what brings him up to town and where he has been “since last Thursday.” Evidently, the reference is to the dinner party held a few nights before. Algy mentions that his Aunt Augusta, Lady Bracknell, and her daughter Gwendolen Fairfax are invited to tea. He testily responds to Jack’s enquiry about eating (he is consuming the cucumber sandwiches Lane has prepared for his Aunt Augusta) with the remark that it is customary to take some slight refreshment at that hour. Ernest, who is really Jack, explains that he has come up to town expressly to propose marriage to Gwendolen. Algy offers to distract his Aunt Augusta while Jack proposes, if Jack will take him to dinner at Willis’s afterwards; Jack agrees. Algy expresses concern over a mysterious person known as Cecily, memorialized in an engraved cigarette case Jack left behind the last time he dined there. The cigarette case is produced, Algy’s suspicions of Jack as an advanced Bunburyist are confirmed, and Jack reveals his life story and his invention of an imaginary younger brother named “Ernest.” Algy explains his intention to avoid his Aunt Augusta’s dinner party that night by invoking his imaginary invalid friend Bunbury’s illness. This subterfuge will free him up for dinner that night with Jack.

The scene is Algernon Moncrieff’s flat in Half Moon Street, Piccadilly. The time is late afternoon, on what will eventually be identified as a Saturday. Lane the butler is making arrangements for tea. Algy refers to an entry in Lane’s butler’s book for “Thursday night,” when Lord Shoreham and Mr Worthing were dining with him, and questions the inordinate amount of champagne consumed by the servants. Lane explains that this is because the wine is of a first-rate brand, superior to what is served in married households. Ernest Worthing arrives. Algy asks what brings him up to town and where he has been “since last Thursday.” Evidently, the reference is to the dinner party held a few nights before. Algy mentions that his Aunt Augusta, Lady Bracknell, and her daughter Gwendolen Fairfax are invited to tea. He testily responds to Jack’s enquiry about eating (he is consuming the cucumber sandwiches Lane has prepared for his Aunt Augusta) with the remark that it is customary to take some slight refreshment at that hour. Ernest, who is really Jack, explains that he has come up to town expressly to propose marriage to Gwendolen. Algy offers to distract his Aunt Augusta while Jack proposes, if Jack will take him to dinner at Willis’s afterwards; Jack agrees. Algy expresses concern over a mysterious person known as Cecily, memorialized in an engraved cigarette case Jack left behind the last time he dined there. The cigarette case is produced, Algy’s suspicions of Jack as an advanced Bunburyist are confirmed, and Jack reveals his life story and his invention of an imaginary younger brother named “Ernest.” Algy explains his intention to avoid his Aunt Augusta’s dinner party that night by invoking his imaginary invalid friend Bunbury’s illness. This subterfuge will free him up for dinner that night with Jack.

Lady Bracknell and Gwendolen arrive for tea, Algy makes his excuses for missing the dinner party that night, and Lady Bracknell urges Algy not to miss the final dinner of the Season, the next Saturday night, since he has promised to arrange the music. Algy takes his aunt into the next room to show her his plans for the music, leaving Jack and Gwendolen alone. The proposal scene between Jack and Gwendolen ensues. Just as Gwendolen accepts Jack’s proposal they are interrupted by Lady Bracknell, who proceeds to question Jack on his suitability for marriage to Gwendolen, meanwhile sending her to the carriage below. The interview initially proceeds favorably, but when Jack reveals that he does not know who his parents are and that he was “found” in a black bag given by mistake at Victoria Station to a kindly old gentleman who proceeded to care for him and raise him, the Lady is outraged, forbids further contact with her daughter, and summarily leaves. Jack, shocked by his experience of Gwendolen’s mother, who he describes as “a monster without being a myth,” tells Algy what has happened. They confirm their dinner for that evening. Suddenly Gwendolen returns and lays plans with Jack to circumvent her mother’s prohibition of further contact. She knows his town address at the Albany but needs his country address, in the likely event that a crisis may occur. Jack tells her the country address, and Algy surreptitiously makes note of it. Gwendolen departs, and Algy reveals that he will certainly go Bunburying the next day if the weather is at all favorable.

The action progresses to Act II. We are now at Jack’s manor house in Hertfordshire. Miss Prism and Cecily are in the garden, doing lessons. Cecily complains about having to study her German, but Miss Prism reminds her that her Uncle Jack laid particular stress on her German as he was leaving for town “yesterday.” We now know that the present day is the next day after Act I. Doctor Chasuble arrives, asks about Mr Worthing’s where­abouts, and then recalls that he “usually likes to spend his Sunday in London.” We are confirmed in our understanding that Act I has occurred on a Saturday, the day before this day. A time scheme for past and present has emerged: Thursday night, Jack is in town, dining with Lord Shoreham and Algy in Half Moon Street; after presumably spending Thursday night in his rooms at the Albany, Jack returns to the manor house in Hertford­shire on Friday; and then on Saturday he travels back to town with the object of encountering Gwendolen and proposing marriage to her, which he does, but then faces the objections of the formidable Lady Bracknell.

It is now the next day, Sunday, and presumably after church time, since Doctor Chasuble has completed his priestly duties and is able to visit Miss Prism and Cecily. (We notice that Miss Prism’s instructional regime is strict enough to include lessons on a Sunday.) Chasuble offers to leave so as to interrupt their studies no further, but Miss Prism’s headache moves her to accept Chasuble’s offer of a walk, and they go off. Cecily, short of temper, sweeps her books onto the ground in frustration, but is interrupted by Merriman, who announces the arrival of Mr Ernest Worthing. It is Algy, dressed as we shall see in full debonair outfit, having brought his luggage with him on this prospective Bunburying adventure. He has with him the personal card of Ernest Worthing that he took from Jack’s cigarette case the day before, enabling him to pose credibly as Jack’s younger brother. When Cecily explains that her Uncle Jack will not return until Monday afternoon, Algy regrets that he will presumably miss him since he must go back up to town first thing that day. (Evidently, fast thinking serves Algy well in his Bunburying exploits.) As Cecily takes Algy inside to satisfy his hunger, Miss Prism and Canon Chasuble return. They are soon interrupted by the unexpected arrival of Jack, dressed in full mourning. Miss Prism remarks that they did not look for him until Monday afternoon, but Jack explains that he has returned sooner than expected: his younger brother Ernest has died. He passed away abroad, in Paris, having expired of a severe chill. Changing the subject, Jack adds that he wants Chasuble to baptize him. Chasuble is astounded, but Jack says he remembers nothing about being baptized before. They appoint the hour of half past five. Cecily comes out of the house, is surprised to see her Uncle Jack, and in such sombre clothes, and tells him his brother Ernest has arrived. Jack’s obfuscation is soon succeeded by outrage as Algy enters, his disguise as Ernest all too transparent. Algy, brazenly maintaining his bogus identity, complains of being treated with coldness by his elder brother. Cecily forces them to shake hands. Merriman enters and explains to Jack that he has put Mr Ernest’s luggage in the room next to his own. It is still early afternoon, and all save Jack and Algy go in to lunch.

Jack complains bitterly about Algy’s subterfuge. He allows no Bunburying here, he insists. He has summoned the dog cart for Algy, who must use it to go back to the station and on to London, by the 4.05 train. Algy agrees to go if Jack will only change his grotesque funereal garb. While Jack is gone, Algy is joined by Cecily, who still knows him as Ernest. They lament his harsh treatment at Jack’s hands. Algy declares his love for her, and Cecily reveals that they have already been engaged for three months. The full story of the engagement, as recorded in Cecily’s diary, is now revealed, much to Algy’s amazement and delight. When Algy discovers that Cecily has always wanted to be married to a man called Ernest, he departs for the rectory, planning to make an appointment with Dr Chasuble to be baptised under the required name.

Merriman enters to announce that a Miss Fairfax has called, looking for Mr Worthing. Cecily asks for the lady to be shown out to the garden. Gwendolen enters, and Cecily calls for tea to be brought. A civil conver­sation quickly turns sour as Cecily and Gwendolen realize they are both engaged to someone called Ernest. The serving of tea brings little relief. A fragile truce is declared and then abandoned as smoldering hard feelings increase. They are interrupted by the arrival of Jack, followed by Algy, and immediately the true identities of Jack and Algy are discovered. The two men, exposed as pretenders, acknowledge their real names. They are left by Cecily and Gwendolen with an unanswerable question: since both men are engaged to someone called Ernest Worthing, where is he? Gwendolen and Cecily join in a sisterly embrace and then depart into the house in high indignation, leaving Algy and Jack to quarrel over muffins and tea cake and the problematic state of relations with Gwendolen and Cecily. Each discovers that the other has appointed a baptism with Doctor Chasuble, but it now seems a fruitless gesture. Consuming endless amounts of muffins does not seem to help, and for the moment they succumb to despair. On this point, the act comes to an inconclusive end.

The action now moves inside to the morning room of the manor house, for Act III. It is still Sunday afternoon. Under questioning from Cecily and Gwendolen, the men readily clarify their desires for seeing them as often as possible — motives the women acknowledge are praiseworthy — but the problem of their Christian name remains. The women are considerably cheered by the news that both Jack and Algy propose to be baptized under the name of Ernest. The issue seems to be settled, when suddenly Lady Bracknell is announced. She has bribed Gwendolen’s maid, found out that her daughter has fled to this country estate, and has followed her post haste, tolerating the indignity of travelling on a luggage train and determined to thwart Gwendolen’s evident intention of pursuing Jack on his home ground. Algy introduces Cecily to Lady Bracknell as his bride-to-be, but Jack explains the clear impossibility of Cecily’s marrying without his consent as her guardian. He will permit such a marriage only when Lady Bracknell allows Gwendolen to marry him, which the Lady categorically refuses to do. They find they have come to a reluctant standstill, but are surprised by Doctor Chasuble, who enters almost as if announcing the time. He explains that all is ready for the christenings — a stunning development, in Lady Bracknell’s view, who believes the idea must surely be premature. It is now 5.30. The afternoon is almost over, and yet it appears that nothing has been resolved.

And then Miss Prism, having been kept waiting in the rectory in mounting frustration, arrives in search of Dr Chasuble. She is cowed to encounter Lady Bracknell, who recognizes her as the nursemaid who took her young nephew out in a perambulator one day years ago and never returned. Miss Prism shamefacedly reveals the facts of the matter. She recounts the story of a black leather bag then in her possession, into which she mistakenly placed the baby, unaccountably depositing the manuscript of a three-volume novel written during her few leisure hours into the basinette of the perambulator. Jack now knows enough to retrieve the leather bag, which he has kept in his bedroom all these years; he brings it to Miss Prism and asks the fateful question of its identity. Miss Prism acknowledges it as indeed her bag, and is grateful to have it restored to her. Jack reveals that he was the baby she placed in it. Miss Prism, aghast, points to the Lady as the bearer of the answer to the question Jack now raises: “Can you tell me who I am?” Lady Bracknell explains that he is the elder son of her departed sister and her husband, General Moncrieff; he is consequently Algy’s elder brother. Gwendolen now raises an additional urgent question: what was his Christian name? Jack has recourse to the Army Lists that line his bookshelves and discovers that, as an eldest son having naturally been named after his father, he is Ernest John Moncrieff. And so Jack discovers he has been telling the truth about his name all his life. He hopes Gwendolen can forgive him for that. She replies that she can, for she feels he is sure to change. Lady Bracknell accuses him of showing signs of triviality, but Jack contradicts her: for the first time in his life, he now realizes the vital importance of being “Earnest.”

The conclusion has come a mere twenty-four hours after the action of the play began.