The plot is organized on two levels: the main plot is the dispute over money matters between the Venetian Antonio and the Jewish money-lender Shylock; the subplot regards the choice of a husband for the rich lady Portia, who lives in Belmont.
FIRST ACT: in a street of Venice Antonio is telling two of his friend, Salerio and Solano, that he has invested all his money in foreign trade. Three other friends are introduced: Bassanio, Gratiano and Lorenzo, who will later elope with Shylock’s daughter, Jessica. Bassanio will travel to Belmont to woo Portia. Meanwhile, in Portia’s estate at Belmont, she speaks with her servant, Nerissa, about the marriage plan that her recently dead father has arranged. According to her father’s will Portia’s suitors must undergo a test which involves choosing among three caskets or chests, one of gold, one of silver, and one of lead. Bassanio needs to obtain a loan from Shylock, but Antonio expresses his contempt for the greedy usurer. Shylock arrives, and conveys his hatred for Antonio as a Christian who despises Jews, denounces usury, and upsets the money-lending trade by not changing interest. Shylock agrees to supply Bassanio with three thousand ducats for three months: if Bassanio fails to repay him, then Antonio must give a ‘pound of flesh’ to Shylock. Antonio agrees to this condition.
THIRD ACT: in Venice Shylock is furious because Jessica has fled his house with his ducats and jewels. In Belmont Bassanio selects the leaden chest and, when he unlocks it, he finds a portrait of Portia. She agrees to marry him while Nerissa and Gratiano announce their plans to wed in a double ceremony. Antonio’s ships have been shipwrecked, so he cannot repay Shylock, and the usurer claims his flesh. While Antonio is in jail in Venice, Portia plans to disguise herself as a lawyer and plead Antonio’s case against Shylock’s suit at the court of the Duke of Venice
FOURTH ACT: the trial takes place at the court of the Duke of Venice. Disguised as a lawyer, Portia offers Shylock a huge sum of money and tries to persuade him to drop the charge against Antonio, but Shylock refuses. Therefore she says that if Shylock sheds a single drop of Antonio’s blood while exacting his revenge, he will be committing a capital crime. Portia then points out that Shylock has committed another crime; he is a non-citizen of Venice who has threatened the life of the citizen Antonio and is therefore subject to the death penalty unless the Duke says otherwise. The Duke of Venice spares Shylock’s life and allows him to keep half of his remaining wealth if he converts to Christianity and gives the other half to Jessica and Lorenzo.
FIFTH ACT: all of the positive characters are in front of Portia’s Belmont mansion and comment upon some of the themes raised in the play. The play ends with musical accompaniment and a happy note.
The Merchant of Venice is one of Shakespeare’s plays which defies easy classification because it analyses serious themes and leaves some issues unresolved.