Act I: Antonio, the Merchant of Venice, discusses his sadness with Salerio and Solanio. Bassanio asks him for a loan, and Antonio says he may borrow on his credit because his money is at sea. In Belmont, Portia discusses her distaste with her suito rs with Nerissa. Back in Venice, Bassanio gets money from Shylock on the condition that if Antonio does not repay in three months, he gets a pound of his flesh.
Act II: The Prince of Morocco arrives to try for Portia's hand. Bassanio and company plan their dinner. In Venice, Shylock tells his daughter Jessica not to go out, but she loves Lorenzo and they escape that evening with her father's valuables. Mor occo picks the Golden Casket, which is wrong, and leaves. Salerio and Solanio, the gossipers, talk of Shylock's anger at finding his daughter and money taken. The Prince of Aragon arrives and tries to win Portia's hand, but incorrectly chooses the silver casket.
Act III: The gossipers reveal that one of Antonio's ships has sunk and that he may be in trouble. Bassanio correctly picks the leaden casket, but later finds out that Antonio owes a pound of flesh to Shylock. Because he will die, he wants to see Ba ssanio again. Bassanio goes to Venice to see him.
Act IV: Shylock rejects an offer from Portia for three times the initial loan because he wants his enemy Antonio dead. Portia and Nerissa disguise themselves as doctor and clerk and go to help Antonio. Portia points out that because the 'bond' they made said Shylock could not have Antonio's blood, he cannot take the flesh and also loses all of his possessions.
Act V: Lorenzo and Jessica are enjoying the night, when Portia and Nerissa return just ahead of Bassanio, Graziano, and Antonio. The wives reveal themselves and the rings they had deceitfully taken.
The summary of this play was taken from http://www.ocf.berkeley.edu/~anthony/Shake2.html