The Cahill family has a secret. For five hundred years, they have guarded the 39 Clues - thirty-nine ingredients in a serum that transforms whomever takes it in

Guardians of the 39 Clues, Dan Cahill and his sister Amy discover that the serum is missing and must race against time to get it back before catastrophe strikes

FINAL HOURS Tick tock. Fifteen-year-old Amy Cahill has only a few days to live. There's a poison coursing through her, and her only chance is to collect ingredi

When the serum of the 39 Clues goes missing, thirteen-year-old Dan Cahill and his older sister, Amy, do whatever it takes to retrieve it.

Amy and Dan dodge the shadow of a man in black as they search for the 39 clues.