The 39 Clues: Cahills vs. Vespers Book 2: A King's Ransom
The 39 Clues: Cahills vs. Vespers Book 3: The Dead of Night
The 39 Clues: Cahills vs. Vespers Book 4: Shatterproof
The 39 Clues: Cahills vs. Vespers Book 5: Trust No One
The 39 Clues: Cahills vs. Vespers Book 6: Day of Doom