Lord Goring waits at the Chiltern home hoping to speak with them. Lord Caversham is also there, and Lord Goring attempts to avoid him. He is unsuccessful, and when he greets his father, Lord Caversham asks whether he has seen the article in the paper on Sir Robert’s decision regarding the Argentine Canal. Lord Caversham reports the high praise Sir Robert has received for denouncing the scheme, and Lord Goring is relieved. Mabel then enters the room, and the three of them discuss Lord Goring’s “heartless” and unruly disposition before Lord Caversham leaves.

Once Mabel and Lord Goring are alone, he tells her he’d like to propose to her—something Lord Caversham frequently suggests he do. She accepts, telling Lord Goring that she adores him. Lady Chiltern then enters, and Mabel and Lord Goring keep the proposal a secret, Mabel telling Lord Goring that she will wait for him under a palm tree by the conservatory. When Mabel leaves, Lord Goring tells Lady Chiltern that he has burned the letter Mrs. Cheveley planned to use against Sir Robert but that she is now in possession of Lady Chiltern’s letter to Lord Goring, which she plans to send to Sir Robert, claiming infidelity.