Sir Robert Chiltern is an “Ideal Husband” to Lady Chiltern. She doesn’t know that he made his
fortune dishonestly: by revealing a Cabin secret to the late Baron Arnheim. The baron’s protégé, and Lady Chiltern’s enemy, Mrs Cheveley
has proof of this and blackmails Sir Robert into supporting a fraudulent canal scheme that would make her rich. Meanwhile Lord Goring, a friend of Sir Robert, and Mabel, Sir Robert’s sister, find a
diamond brooch that Lord Goring knows to have been stolen in the past by Mrs Cheveley.
When Mrs Cheveley realises that Sir Robert has gone back on his promise because of Lady Chiltern, she exposes Sir Robert in front of his wife, who refuses to forgive him.
Lady Chiltern then writes a letter which, although is asking for Lord Goring’s help, might
also be read as a love letter. After receiving the letter Lord Goring’s
father drops in, followed by Sir Robert, who has come to seek his
friend’s counsel. Meanwhile Mrs Cheveley, who has been mistakenly
allowed in by the butler , is found eavesdropping on the two friends’
conversation by Sir Robert himself, who accuses Lord Goring of plotting
After Lord Goring confronts Mrs Cheveley, the latter makes
a proposal: she will give up Sir Robert’s incriminating letter for
Lord Goring’s hand in marriage. Lord Goring declines and frames Mrs
Cheveley with the diamond brooch. She gives in but steals Lady Chiltern’
s compromising letter planning to make Sir Robert believe his wife is
in love with Lord Goring. Mrs Cheveley’s plan doesn’t succeed because,
after Sir Robert denounces the scheme, he receives the letter and
interprets it as an apology addressed to himself. Nevertheless Lady
Chiltern is forced to explain the true nature of the letter and of the
previous night’s events, to convince Sir Robert of Lord Goring’s
integrity and to allow his to marry Mabel.