Alexandria "Alex" Andros is a fictional character from the popular book series The 39 Clues. She is known for her intelligence, resourcefulness, and strong leadership skills. Alex is a member of the Cahill family, a powerful and influential family that plays a central role in the series' quest for clues and treasures. In the series, Alex often takes charge during challenging situations, showcasing her ability to think critically and adapt quickly. Her character represents the themes of adventure and discovery, as she navigates through various challenges alongside her family members and allies in pursuit of the ultimate prize.