The Prince of Aragon has arrived at Belmont to try his hand at the riddle of the caskets. Portia tells the Prince the rules of the riddle: if he chooses the casket that contains her portrait, they will be married immediately; if he fails, he must depart without another word. Aragon adds that he is bound by oath to three further conditions: (1) never to tell anyone which casket he chose; (2) never to seek the hand of any other woman in marriage, if he fails; and (3) to leave immediately, if he fails. Portia confirms that anyone who wants to woo her must agree, in advance, to each of these terms.
One again, Shakespeare goes to great length to emphasize the legal ramifications of the riddle. If he should "interpret" incorrectly, the Prince will be unable to produce an heir. He will forfeit his future.
Aragon puzzles over the inscriptions on the three chests. He rejects the lead one ("Who chooseth me, must give and hazard all he hath") because he refuses to give or hazard anything for something so ugly and plain. He also rejects the gold one ("Who chooseth me shall gain what many men desire") because he thinks only someone who looks skin deep would take that one and he refuses to be like "many men." Finally, he turns to the silver one: "Who chooseth me shall get as much as he deserves" (36). He notes how much better the world would be if every man only took what he deserved, and asks for the key.
As was the case in 2.7, Shakespeare extends the actual scene of interpretation, making it suspenseful and dramatic. And once again, the struggle to determine whether gold, silver, or lead will lead to love explicitly links love and greed (or commerce), which also appeared together in the course of Jessica's elopement.
Portia gives it to him. But when Aragon unlocks the casket, inside he finds a "portrait of a blinking idiot" and a rhyme that mocks him as a fool and instructs him to leave Belmont. Embarrassed and disappointed, Aragon departs, remarking that he will keep his oath and patiently bear the fate that he has earned. He exits with his entourage.
While the scene has much the same effect as Morocco's disappointment in 2.7, there is an important difference: now Portia—and the audience—know which casket is the correct one: the lead.
As Portia and Nerissa draw a curtain in front of the caskets, a messenger enters with the news that a young Venetian has arrived at the gate to announce the arrival of a lord who has come bearing "gifts of rich value" and is a "likely ambassador of love." Portia is very excited. Nerissa sighs that she hopes the Venetian is Bassanio.
Having echoed the frustration and sense of powerlessness that she expressed in 1.2, Portia shows her first real glimpse of excitement with Bassanio's arrival.