The Madrigals.
I believe they are in Madrigal. I'm not sure.........
no
Madrigals
Tomas.
janus
Hamilton Holt is in the Janus branch of the Cahill family in the book series "The 39 Clues." The Janus branch is known for their expertise in deciphering codes and puzzles.
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.
Irina Spasky, Ian Kabra, Natalie Kabra
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.
the Janus branch is from Jane Cahill, its symbol is a wolf, they are he artistic branch. the Ekaterina branch is from Katherine Cahill, its symbol is a dragon, they are well known inventors and are famous for their intelligence the Tomas branch is from Thomas Cahill, the symbol is a bear, they are the athletic ones in the family the Lucian's are from Luke Cahill, their symbol is the two snakes on a pole, they are known for their battle statistics and their determined minds, willing to risk anything to win and last but not least the Madrigals, the are the descendants of Madeline Cahill, she is the last child born to Olivia and Gideon Cahill and her mother taught her that she needed to reunite the family. Their symbol is usually a "C". but they also use an "M" sometimes too.
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.