(This is a really long book, so I 'll just put in the basics).
The three people that Dantes swears vengance against are the Count de Morcerf, Baron Danglars, Villefort.
I 'll start with the simple one first. Danglars was one of the men that helped frame Dantes. He clawed is way up the social ladder because of his great wealth. He is very determined to keep it though. He abandons his wife and tries to sell his daughter Eugenie into a loveless marriage for three thousand francs. Danglars has a lot of bills and debts, he tries to escape with five million francs, but is captured by Luigi Vampa under Edmond 's command and is starved into giving up his money. After he repents and Edmond is satisfied, he is let go, but without his money.
Mondengo/Count de Morchef married Mercedes and they had a son names Albert (unlike in the movie, it is Ferdanand 's son). Through the Count, charges are brought against him that by killed Ali Pasha, the ruler of Janina, and sold his wife and duaghter in to slavery. He is about to be let off, when Haydee, a woman introduced as one of the Count 's servants steps forward. She is the daughter of Ali Pasha and has evidence that shows that he was the murderer and did sell her and her mother. Albert become angry with the Count because of this and wants to duel him. Mercedes comes to Edmond and begs him not to kill Albert and he promises not to. A minute before the duel is scheduled to start Albert comes and calls it off, his mother told him about all that his father had done. Albert goes off the Africa to start a new life with the name Herrerra, his mother 's maiden name and Mercedes