39 Clues #7: The Viper's Nest

The most dangerous secret in Amy and Dan's past is unveiled in Book 7 of the #1 New York Times best-selling series. It's no longer a game. The body count is rising. Shaken by recent events, Amy and Dan flee to an exotic land and trace the footsteps of their most formidable ancestor yet: a military leader of mythic proportions. Yet just as the siblings begin to master the art of ancient warfare, they confront a dangerous enemy that can't be felled with a sword: the truth. With the stakes higher than ever, Amy and Dan uncover a devastating secret that changes everything.