The Count of Monte Cristo.

Edmond Dantes is falsely accused by those jealous of his good fortune, and is sentenced to spend the rest of his life in the notorious island prison, Chateau d'If. While imprisoned, he meets the Abbe Faria, a fellow prisoner whom everyone believes to be mad. The Abbe tells Edmond of a fantastic treasure hidden away on a tiny island, that only he knows the location of. After many years in prison, the old Abbe dies, and Edmond escapes disguised as the dead body. Now free, Edmond must find the treasure the Abbe told him of, so he can use the new-found wealth to exact revenge on those who have wronged him...