He is worse than nothing, for he is in debt to his friend, and that friend for him is now in danger of his life. For the three months allowed by Shylock for the payment of the debt are over, and as not one of Antonio's ships has returned, he cannot pay the money. Many friends have offered to pay for him, but Shylock will have none of their gold. He does not want it. What he wants is revenge. He wants Antonio's life, and well he knows if a pound of flesh be cut from this poor merchant's breast he must die.
And all for three thousand ducats! "Oh," cries Portia when she hears, "what a paltry sum! Pay the Jew ten times the money and tear up the bond, rather than that Antonio shall lose a single hair through Bassanio's fault."
"It is no use," she is told, "Shylock will have his bond, and nothing but his bond."
If that be so, then must Bassanio hasten to his friend to comfort him at least. So the wedding is hurried on, and immediately after it Bassanio and Gratiano hasten away, leaving their new wives behind them.
But Portia has no mind to sit at home and do nothing while her husband's friend is in danger of his life. As soon as Bassanio has gone, she gives her house into the keeping of Lorenzo and sets out for Venice. From her cousin, the great lawyer Bellario, she borrows lawyer's robes for herself, and those of a lawyer's clerk for Nerissa. And thus disguised, they reach Venice safely.
This part of the story has brought us to the fourth act of the play, and when the curtain rises on this act we see the Court of Justice in Venice. The Duke and all his courtiers are present, the prisoner Antonio, with Bassanio, and many others of his friends. Shylock is called in. The Duke tries to soften the Jew's heart and make him turn to mercy, in vain. Bassanio also tries in vain, and still Bellario, to whom the Duke has sent for aid, comes not.
At this moment Nerissa, dressed as a lawyer's clerk, enters, bearing a letter. The letter is from Bellario recommending a young lawyer named Balthazar to plead Antonio's cause. This is, of course, none other than Portia. She is admitted, and at once begins the case. "You stand within his danger, do you not?" she says to Antonio.
"ANTONIO. I do.
PORTIA. Then must the Jew be merciful.
SHYLOCK. On what compulsion must I? Tell me that.