39 clues. Cahills vs. Vespers

Vesper One commands Dan and Amy Cahill to steal the Golden Jubilee, one of the world's largest diamonds, but what they do not know is that the Jubilee theft is just a setup and someone is going to die.

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.

Siblings Amy and Dan must find out who the Vesper mole is in their innermost circle.

Siblings Amy and Dan must find another way to outwit the Vespers when they target and kidnap Dan's only friend, eleven-year-old Atticus.

Thirteen-year-old Dan Cahill and his sister, Amy, figure out Vesper One's endgame and realize they must stop the organization from using their ransoms to harm millions of people.

After seven of their relatives are kidnapped, Amy and Dan Cahill are pushed to their breaking point as they search for the priceless artifacts Vesper One demands in exchange for the hostages.

Siblings Amy and Dan must find another way to outwit the Vespers when they target and kidnap Dan's only friend, eleven-year-old Atticus.

After the Vespers kidnap a number of Cahills, it's up to Amy and Dan to track down the priceless artifacts needed to free the hostages.

Thirteen-year-old Dan Cahill and his older sister Amy race against time to find an ancient map that has not been seen for half a century and use it to redeem their family members who have been kidnapped by a sinister organization called the Vespers.

Amy and Dan find themselves in a new global race but this time, they have just days to fulfill a bizarre ransom request or the Vespers will kill their kidnapped friends.