Chapter 16: Dantes returns to Marseilles, visiting the inn that Caderousse and his family own. Dantes disguises himself as a priest, telling them the story of a naive Dantes who died in prison, wanting to reward his friends with the only possession he had- a diamond given him by an Englishman. The "priest" says that he visited the dying Dantes and was glad to do him the favor of dividing the money of the diamond among his friends. One of these friends is Caderousse (which is ironic since Caderousse was one of the men who betrayed Dantes).
During this meeting, the priest learns that Mercedes has married Fernand, though she never loved him. Danglars has grown very rich as an investment banker. Learning that all of Dantes' other friends have betrayed him, the priest leaves Caderousse the diamond in its entirety. Caderousse and his wife greedily accept the gift.
Chapter 17: Dantes, again disguised, meets with the Inspector of Prisons who has invested heavily in Morrel and Son. Since now this company has had very bad luck and is no longer valuable, the inspector is surprised when Dantes offers to buy his large investment. Dantes is eager to help Morrel any way he can after learning that he tried to secure the boy's release from prison and also provided for Dantes' dying father.
Chapter 18: Dantes, again disguised as an English businessman, visits Morrel, who is now approaching bankruptcy. During their meeting, it's learned that the Pharaon has been lost. This ship was the only chance for Morrel to pay off his debts. Dantes promises to extend the debt which Morrel now owes him. When leaving, Dantes tells Morrel's daughter to follow the instructions of a letter to be sent to her from Sinbad the Sailor.
Chapter 19: Morrel's daughter gets a letter from Sinbad the Sailor, telling her to go to a building to snatch the red purse. This purse was given Dantes' father by Morrel years ago to help the old man pay for food.
Soon Morrel tells his son that he is going to kill himself. Just when he is about to pull the trigger, his daughter bursts into the room, showing him the purse with a note saying that his debt has been paid in full. The purse also contains a costly diamond. Later, the Morrel family learns that the Pharaon is still alive and coming into harbor. It seems Dantes has paid to build another Pharaon to provide for Morrel and his family.
Dantes reflects on his own generosity, "and now, farewell to kindness, humanity and gratitude... I have substituted myself for Providence in rewarding the good; may the God of vengeance now yield me His place to punish the wicked!"
Chapter 20: This chapter marks a shift in focus. Now the setting is Rome, during the famous carnival of the city. Two rich Frenchmen, Franz and Albert are staying in the same hotel as the Count of Monte Cristo, Dantes' latest disguise. When the two men try to buy a carriage and discover that none are available, Monte Cristo offers his carriage to them.
Soon Monte Cristo takes the two men to see an execution with him. During the execution, the count seems to ramble to himself about death, saying things such as, "an eye for an eye, and a tooth for a tooth." This foreshadows the count's desire for vengeance.