Shatterproof (The 39 Clues: Cahills vs. Vespers, Book 4)

In the fourth installment of the CAHILLS VS. VESPERS series, Amy and Dan find themselves as Interpol's most wanted after their daring heists, facing a perilous mission to steal the world's largest diamond. As they navigate an ancient city filled with dangerous secrets, they must contend with a Vesper mole sabotaging their efforts and a deadly enemy whose thirst for vengeance puts them in grave danger.