Amy and Dan Cahill are in the lead to find thirty-nine clues that safeguard a great power, and are in possession of a coded sheet of Mozart's music that will help them find the next clue while their relatives follow in close pursuit. Does not include game cards.

Thirteen-year-old Dan Cahill and his older sister, Amy, thought the search for the thirty-nine clues leading to the source of their family's power was over, but when Cahills are kidnapped by the Vespers, Amy and Dan find themselves with only a few day to fulfill a bizarre ransom request before their friends start dying.