The Countess of Rossillion, recently widowed, sends her son Bertram, accompanied by his braggart companion, Parolles, to the court of the ailing King of France.
Helena lives in the Countess' house as a dependent; her father was the Count's physician and bequeathed to his daughter his healing remedies. Secretly in love with
Bertram although far beneath him in class, Helena follows him to court where she persuades the King to allow her to choose a husband in return for restoring the King's health.
When she chooses Bertram, however, he angrily rejects her. Forced to marry her by the King, he refuses to honor his vows until she wears the ring which will never leave
his finger and has a child by him. He flees to the wars in Italy and promptly wages a campaign there to seduce a young virgin, Diana. Helena, following him in secret,
conspires with Diana to foil Bertram with an exchange of rings and a bed-trick. In the parallel comic subplot, Parolles is captured by Bertram's companions and punished
as a braggart soldier and hypocrite. Bertram comes to see the truth about Parolles, which the King's counsellor Lord Lafew and the Countess' clown Lavatch have already made abundantly clear.
In the stunning final scene of the play, Diana and Helena reveal their deceptions to the assembled court at Rossillion, a humiliated Bertram publicly accepts Helena as his wife,
and, in the words of the King, "all yet seems well."