One small girl. One giant mystery.
Max isn’t thrilled about spending the summer with her dull Great Aunt Elodie in Istanbul. But everything changes when the legendary Heartbreak Diamond vanishes — and Max is swept into a whirlwind chase across Europe.
With diamond smugglers, undercover detectives, and secretive strangers at every turn, Max must uncover the truth before it’s too late. But as the train speeds toward its final stop, she begins to wonder… could the real thief be closer than she thinks?