I'm so glad to know you enjoyed The Count of Monte Cristo!
Although it's been a long time since I read it, I agree it's very
exciting reading. So, here are three titles I'd like to recommend.

Fever, 1793 by Laurie Halse Anderson.
In 1793 Philadelphia, sixteen-year-old Matilda Cook, separated from her sick mother, learns about perseverance and self-reliance when she is forced to cope with the horrors of a yellow fever epidemic.

 Here are three titles I hope you'll find deliciously spine-chilling.

The Old Willis Place by Mary Downing Hahn
Tired of the rules that have bound them ever since "the bad thing happened," twelve-year-old Diana ignores her brother's warnings and befriends the daughter of the new caretaker, setting in motion events that lead to the release of the spirit of an evil, crazy woman who once ruled the old Willis place.

Undercurrents by Willo Davis Roberts