Madrigals
Amy and Dan are part of the Cahill family, a secret society in The 39 Clues series. They belong to the Madrigal branch of the Cahill family, one of the most secretive and enigmatic branches.
They are Madrigals. It comes from Grace and Hope's side of the family. Amy and Dan learn this in Viper's Nest, Book7.
Their branch is....... madrigal (srry i wanted it to be dramatic) :D
In Book Seven: The Viper's Nest: Amy and Dan Cahill figure out they are Madrigals
Amy and Dan Cahill are part of the Ekaterina branch in the 39 Clues series. The Ekaterina branch is known for their intelligence and passion for knowledge.
i believe Amy and Dan are Madrigals.
Grace and Fiske Cahill's car crash was orchestrated by Isabel Kabra, a member of the Lucian branch of the Cahill family. She was under orders from her mother, Cora Wizard, who is a part of the Ekaterina branch.
Okay, here's the truth by studying the Cahill family tree of the Oh family and Grace's family. Grace's grandfather Henry was a Madrigal and married another Madrigal: Flora, who had James Cahill, Grace's father. But Flora died and Henry married an Ekat; Hae Oh. They kept the name Oh and had their offspring, Gordan and Bae. Then Gordan had Alistar. So Grace is a Madrigal and not an Ekat, it's just that James and the Oh twins are half brothers.
In the book THE VIPER'S NEST it reveals the Dan and Amy are Madrigals.
They are Madrigals. So are Grace and Hope Cahill.
They are Madrigals descended from Madeline Cahill through Grace and Hope Cahill.
Amy and Dan are Madrigals. The Madrigals decended from Madeline Cahill. Olivia Cahill (the original cahill) was pregnant with her when Olivia died. Madeline then decided to carry out her mother's wishes. Madrigals try to keep the other branches from finding all the 39 clues. Hope this helps! :)