The 39 Clues : The Maze of Bones

The story begins with the death of Grace Cahill, the matriarch of the powerful Cahill family. Orphans Amy and Dan discover that, instead of a traditional inheritance, they must choose between a million dollars or the first of thirty-nine clues leading to a potentially life-altering treasure. They opt for the clues, setting them on an exhilarating and dangerous adventure involving other family members, each vying for the same clues scattered around the globe.
The siblings begin their journey in the family's mansion, which is soon set ablaze, forcing them to escape with only a few clues. Their adventure takes them to various historical locations, where they have to navigate through traps and solve puzzles that unravel the history of their family. They encounter various family rivals, such as the Kabra siblings and others, each representing different branches of the Cahill family.
Throughout the novel, themes such as family loyalty, cunning, and the pursuit of power are explored as Amy and Dan uncover not only the clues but also their unique talents and potential as influential players in their family's legacy.