A comedy in five acts, produced about 1602-03 and published in the First Folio of 1623 from the author's fair papers or a transcript of them. The principal source of the plot is a tale in Giovanni Boccaccio's Decameron.

Helena, the orphan daughter of a famous physician, is the ward of the Countess of Rousillon, and hopelessly in love with her son, Count Bertram, who has been sent to the court of the King of France. Despite her beauty and worth, Helena has no hope of attracting Bertram, since she is of low birth and he is a nobleman. The Countess, however, is well aware of Helena's feelings (and indeed approves of them).

Against this backdrop, the King of France has taken deathly ill. Bertram has left to attend the King's court; Helena soon follows him to Paris, bearing a prescription of her father's that she feels might hold a cure for the ailing king. The cure earns her the gratitude of the King, who keeps a bargain between them that she can have her pick of the bachelors at his court. Helena, of course, picks Bertram, who is quite put off by the prospect. To Bertram, Helena is beneath and unworthy of his notice. Nevertheless, the King will keep his word-Bertram is ordered to marry her. Under protest, Bertram assents to the marriage, but slips off to a war in Tuscany with his cowardly companion, Parolles.

The Countess sends Helena home, and receives a letter from Bertram informing her that he will never be her true spouse unless she can get his family ring from his finger, and become pregnant with his child--neither of which, he declares, will ever happen. The Countess, who loves Helena and approves of the match, tries to comfort the distraught young woman, who soon departs Rousillon, for Florence where she arrives in the guise of a pilgrim

Meanwhile, in Florence, Bertram has become a general in the Duke's army. Helena comes to the city, and discovers that her husband is trying to seduce the virginal daughter of a kindly Widow. It is this Widow, with whom she coincidently winds up lodging, and whose daughter, Diana, is ironically the object of Bertram's affections. With Diana's help, Helena aims to trap Bertram he gives Diana his ring as a token of his love. When he comes to her room at night, Helena is in the bed, and they make love without him realizing that it is she. She exchanges a ring that the King had given her for Bertram's, thus accomplishing both terms of Bertram's challenge. Thus is born one of the more famous ploys in Shakespeare's repertoire: the original bed trick. At the same time, two lords in the army expose Parolles as a coward and a villain, and he falls out of Bertram's favour. Meanwhile, false messengers have come to the camp bearing word that Helena is dead, and with the war drawing to a close, Bertram reckoning that he is clear of any responsibility to the wife he never wanted, and decides to return to France. Unbeknownst to him, Helena follows, accompanied by Diana and the Widow.

In Rousillon, everyone is mourning Helena as dead. The King, who is visiting, and consents to Bertram marrying the daughter of an old, faithful lord, named Lafew. However, he notices a ring on Bertram's finger that formerly belonged to Helena--it was a gift from the King after she saved his life. (Helena gave the ring to Diana in Florence, and she in turn gave it to her would-be lover.) Caught in a series of lies Bertram at a loss to explain where it came from. The King, supposing Bertram has murdered Helena, has him arrested. Adding to Bertram's misery, Diana and her widowed mother both arrive, demanding justice, unearthing even more of Bertram's lies.

Helena finally appears-bearing Bertram's ring and carrying his child-and reveals the truth to all, and informs her husband that both his conditions have been fulfilled. Chastened, Bertram consents to be a good husband to her, and there is general rejoicing.