In Act III Sc 2. Bassanio has chosen correctly the leaden casket and has won the hand of Portia. Everyone is extremely happy and Nerissa exclaims:
But just then, Salerio arrives from Venice with a letter for Bassanio. As Bassanio reads the letter he grows paler and paler leading Portia to remark impatiently that she must know all the contents of the letter:
"There are some shrewd contents in yon same paper,
That steals the colour from Bassanio's cheek:
Some dear friend dead; else nothing in the world
Could turn so much the constitution
Of any constant man. What, worse and worse!
With leave, Bassanio: I am half yourself,
And I must freely have the half of anything
That this same paper brings you."
Bassanio then tells her that his dearest friend Antonio the merchant who has sponsored all his efforts to win her is now bankrupt because all his ships have been lost at sea; and worse Shylock the jew from whom he has borrowed the money for the trip to Belmont is threatening to sue his friend Antonio who had stood surety for the sum of 3,000 ducats. Bassanio then reads out aloud the pathetic plea of Antonio to see him once before he dies:
"Sweet Bassanio, my ships have all
miscarried, my creditors grow cruel, my estate is
very low, my bond to the Jew is forfeit; and since
in paying it, it is impossible I should live, all
debts are cleared between you and I, if I might but
see you at my death. Notwithstanding, use your
pleasure: if your love do not persuade you to come,
let not my letter."
This is why Bassanio begins to look pale on reading Antonio's letter.