In "The Count of Monte Cristo" the atmosphere, or mood/tone fluctuates beginning with the foreboding tone of the first chapters as Edmund Dantes returns in the merchant ship on which the captain fatefullly dies. Later, when the joyous Edmund Dantes dines with his fiancee and "friends," he feels in Chapter 3 the presence of Fate:  "I cannot help thinking it is not man's lot to attain happiness so easily.  Good fortune is like the palaces of the enchanted isles, the gates of which are guarded by dragons.  Happiness could only be obtained by overcoming these dragons."

The atmosphere of looming Fate becomes even more foreboding as Dantes is falsely thrown into prison for fifteen years. At this pointl, the tone is somewhat despairing.  However, Dantes receives two gifts from Fate, the friendship of the abbe, and, by the death of his friend, freedom and a treasure with which Dantes effects his revenge upon his enemies. So, while the tone changes from despair, there is yet a darkness to the atmosphere as Dantes acts, in his words, as the emissary of God/Fate. 

However, there is a price to be paid for seeing revenge that is not man's to perform; Dantes loses a cherished love, but does find redemption.  In the end, the tone is one of faith: "Wait and hope."