Disguised, Edmond returns to Marseille, where he discovers that his father is dead and that Mercedes has married and moved to Paris. He heads to the island of Monte Cristo and finds the enormous treasure. Transformed into the mysterious Count of Monte Cristo, Edmond begins his revenge.

Edmond frees the slave Haydée, daughter of Ali Pascha, and takes her to Paris. At a ball, Haydée reveals that Fernand betrayed her father. Mercedes begins to suspect that there is something wrong with the count's identity.