Deze spannende serie volgt een machtige familie die een eeuwenoude vijand onder ogen moet zien die opnieuw is opgedoken om hun bestaan te bedreigen. Wanneer belangrijke familieleden worden ontvoerd, moeten de overgeblevenen zich verenigen en aan een gevaarlijke reis beginnen. Ze zullen hun verstand en moed moeten gebruiken om geheimen te ontrafelen en hun dierbaren te redden van een schurk die hen te slim af is. Het is een race tegen de klok vol intriges en actie.
Unable to return to their normal lives despite the end of the Clue hunt, new Madrigal leaders Amy and Dan anxiously prepare for a retaliatory strike by the Vespers, who kidnap a number of Cahill family members and demand that Amy and Dan steal a famous painting.
After seven member of their family are kidnapped by a organization called the Vespers, Dan and Amy Cahill must race against time to track down an ancient map to pay as ransom to bring the hostages home.
When the Vespers continue their abductions and cross a line by kidnapping Atticus, an 11-year-old non-Cahill civilian and Dan's only friend, Dan and Amy confront their biggest challenge ever in order to keep Atticus alive.
Targeted by Interpol after a series of spectacular heists, a reluctant Amy and Dan are ordered by Vesper One to steal the world's largest diamond, a demand that is challenged by their efforts to rescue the Cahill hostages and stop a Vesper mole.
When seven members of their family were kidnapped, thirteen-year-old Dan Cahill and his older sister, Amy, got ready for the fight of their lives. But their enemy, a terrifying group known as the Vespers, remained frustratingly elusive. They stay in the shadows, picking off Cahills one by one
After delivering the last ransom, Amy and Dan discover that Vesper One has a terrifying plot and they race against time to stop him from harming millions of innocent people.