What happens when Bassanio chooses a casket in The Merchant of Venice?
In Act 3 of the play, Shakespeare resolves the casket plot. By this time in the play's action, the Prince of Morocco has already chosen the gold casket--based on appearance--and the audience knows that his is an incorrect choice. Similarly, the Prince of Aragon chooses the silver casket, insulting Portia in the process,and leaves Belmont emptyhanded. By the time Bassanio travels to Belmont from Venice, the audience knows which casket he needs to choose. Portia does help hint at the right box by playing a song which alludes to the correct choice, and Bassanio does indeed choose the lead casket, winning Portia's hand in marriage.
After the hero reads the casket's riddle, he asks Portia to marry him, and she bestows upon him literally all her worldly goods and her heart. Their happiness is short lived, though, for at this point in the play, news arrives that Antonio is serious trouble in Venice. After a quick wedding with Portia, Bassanio hurries to Venice to help his friend to whom he is indebted, so there is no time to revel in his correct choice.