Machevill opens the play by offering a story about a Jewish man that becomes rich by the words of Machiavelli who wrote The Prince. Machevill also notes that he is telling a tragic story about the Jewish man. Barabas is told that he and other Jews must give the state half of their wealth in order to help the local government. This help is given in the hope the Turks will accept the tribute owed to them. The home of Barabas is turned into a convent and later, he gets the idea to have his daughter Abigail become a Christian in the hope that she can smuggle out some of the treasure Barabas has hidden in his home.
Though Abigail loves a man named Mathias, Barabas seeks revenge on Ferneze. As a result, Barabas uses Lodowick to get revenge on Ferenze. Soon Barabas manipulates both men into competing for the affections of his daughter Abigail. Both men then want revenge on the other for courting Abigail. Barabas encourages this by producing a letter that would indicate that Matthias has challenged Lodowick to a duel.