Thirteen-year-old Dan Cahill and his older sister, Amy, are the latest guardians of the Clues -- thirty-nine ingredients in a serum that transforms whomever takes it into the most powerful person on earth. They think they've done everything right, but a tiny mistake leads to catastrophe. The serum is missing and Dan and Amy have to get it back and stop who stole it ... before it's game over.

A million dollars, or a clue? Police report a break-in at an elite hotel, and the suspects sound suspiciously like Amy and Dan. There's a car and speedboat chase and an angry mob! When there's a clue on the line, anything can happen.