Hello, my name is Ernest. (Act I, Lines 1-78)
For the young Victorian man, the double life is the good life. Jack and Algernon both have secret identities and activities. Up until now, they have both seamlessly gone from city life to country life, using their double identities to make things more convenient. Jack’s life is about to get a lot more difficult.
Who am I? (Act I, Lines 79-300)
When Lady Bracknell finds out Jack is an orphan, she sets up the challenge of the play for Jack: find a family—and a good one—or lose Gwendolen. In the meantime, Algernon prepares to come to Cecily as the man of her dreams, Ernest.
Ernest is dead… or is he? (Act II, Lines 1-247)
To make his life easier, Jack kills off Ernest and comes home announcing that his unfortunate brother has died in Paris of a severe chill. Interestingly, Ernest has just come home. We find out that it's really Algernon and he’s come to court Cecily. Enraged, Jack tries to make Algernon leave, but Algy won't leave until he has Cecily's hand in marriage.
Okay, there’s no Ernest. (Act II, Lines 248-396)
Gwendolen’s arrival makes the façade harder and harder to maintain. After a jealous spat over tea, Gwendolen and Cecily discover the truth: there is no Ernest. One Ernest is actually Jack, and the other is actually Algernon. The women’s indignation is short-lived, especially when they learn their men only lied out of love for them.
Can we get married yet? (Act III, Lines 1-108)
Everything’s fine and dandy until Lady Bracknell arrives on the scene. She’s still all high-and-mighty about Jack’s "terminus" of a family (III.61). But little Cecily? Worth a million bucks? Of course she’s the perfect girl for Algy. Unluckily, Jack, Cecily's legal guardian, is having none of it. And guess what? Cecily doesn’t come of age until she’s thirty-five.
Meet my unfortunate brother… (Act III, Lines 109-155)
Miss Prism has deep, dark secrets. Her novel-and-handbag switch has caused all this trouble. Almost thirty years ago during her daily walk, she mistakenly put baby Jack in her handbag and the novel in the stroller. She dropped off the handbag at Victoria Station. So Jack does have a younger brother—Algernon!
I told you I was Ernest. (Act III, Lines 156-181)
So we know Jack’s real last name is Moncrieff, but what about his first name? Oh, named after his father? Doesn’t help that everyone just called him the General. Consulting the Army List of registered Generals confirms that Jack's real name is Ernest! Everyone can get married now.