Amethysts and Arson (Gems and Espionage #6)
Lynn Gardner

Bart’s uncle, an arson investigator, has been receiving anonymous and mysterious clues to crimes planned but not yet committed. Allison and Bart must call upon all of Anastasia’s resources to stop this madman from killing hundreds of innocent people and destroying a dozen significant historical sites out of some twisted and unexplainable drive for revenge. A dozen bombs have been hidden in sites across the southern United States, and in a race against time, Allison and Bart must find and disarm them before they explode. Can they do it?