Scene 1 of Act III begins with Salerio and Solanio talking about the poor state of Antonio's finances. Salerio reveals that one of Antonio's ships has been shipwrecked. Shylock enters, and is mocked about the disappearance of Jessica. Shylock shows how fixated he is on revenge against Antonio. It is clear he is after revenge, not money by this stage. Tubal, a friend of Shylock enters when Salerio and Solanio have left, and reveals that Antonio has lost another ship, but also that Jessica has squandered Shylock's money. Tubal seems to goad Shylock into ever-greater determination to gain revenge.
Scene 2 moves to Belmont. Portia asks Bassanio to wait to choose, showing she wants him to select the correct casket. However, Bassanio refuses, wanting to take the test straight away. Portia, in a speech, praises him and wishes him the best. Tension is increased as Bassanio takes time to ponder the matter. Bassanio reveals his thinking, going for the leaden casked because he is suspicious of outward appearance. The casket contains a portrait of Portia and a note of congratulation. Portia gives herself and her wealth to Bassanio and also gives him a ring but only with the promise that if he takes his ring from his finger that will symbolise the end of their love. Bassanio takes an oath never to be parted with the ring.
There is a celebration. Gratiano decides to share the news of his impending wedding with Nerissa. However, Salerio arrives with Jessica and Lorenzo and changes the mood. He delivers a letter from Antonio to Bassanio, revealing his loss of his ships and that Shylock is insistent on collecting his "bond." Portia initially wants to marry Bassanio before he leaves with full permission to pay whatever it takes to settle the debt. However, when she realises how urgent the matter is, she sends Bassanio straight away to help his friend.
Scene 3 represents another shift back to Venice, with Antonio encountering Shylock on the streets. Antonio attempts to remonstrate with Shylock, but Shylock ignores him, only saying that he will have his "bond." Solanio, who is with Antonio, tries to lift his spirits, but Antonio appears resigned to his inevitable death, knowing that the Duke will want to uphold law and order. Shylock therefore has a legal right to see the fulfilment of the bond made. Antonio only wants to see Bassanio one last time before his seemingly inevitable death.