"I know exactly who I am. I'm Grace Cahill."
Grace lost her father, mother, husband, daughter, son-in-law, and much much connection to her brother, and had to lie to and abandon her grandchildren, all due to the 39 Clues. Her life was tragic, but that by no means made her colder, except towards those responsible. She was an extremely nice person, however the Holt family described her as a witch. Perhaps this was because Eisenhower did not help Hope and Arthur Cahill when they were dying. She was the Madrigal branch leader, but told nobody except her siblings Fiske and Beatrice, her lawyer William McIntyre, and her daughter, Hope Cahill.
- Rebbeca Schnieder - Maternal Grandmother
- Eijah Green - Maternal Grandfather
- Flora Cahill St. James - Paternal Grandmother
- Henry Cahill - Paternal Grandfather
- Hae-In Oh - Paternal Step-grandmother
- Bae Oh - Paternal Uncle
- Gordon Oh - Paternal Uncle
- Lin Kim - Paternal Aunt-in-Law
- Alistair Oh - Paternal Cousin
- Beatrice Cahill - Sister
- Stephano Breglio - Divorced Brother-in-Law
- Jean-Luc Benoit - Divorced Brother-in-Law
- Sergei Baskov - Divorced Brother-in-Law
- Fiske Cahill - Brother
- Nathaniel Hartford - Husband
- Hope Cahill - Daughter
- Arthur Trent - Son-in-Law
- Amy Cahill - Granddaughter
- Dan Cahill - Grandson
Grace Cahill changes her will during the last five minutes of her life. This new will sets the "official" Clue hunt in motion. She then dies because of cancer.
This shows Grace's first adventure and her first encounter with a vesper, George S. Patton. Grace discovers a Morse Code message to her father, James Cahill, who is no longer an active Madrigal, The message tells her to go to Casablanca and seek out Patton. Patton finds Gideon's Ring , what the message told Grace to get. Grace steals the ring back and gets home to Monaco before Patton realises it is missing.
- Can fly a plane. Her plane is called "The Flying Lemur."
- She is very good at security.
- She is rich.
- Can speak 12 languages fluently. 6 by 18.
- She knows how to use any weapon from a rifle to a boomerang, with which she is unrivaled.
- Talented cartographer and managed to make her own globe using the knowledge she collected during her travels.
- Used dart-gun
Apparently she came close to assembling the 39 Clues but did not succeed in collecting all of them.
Grace Madeleine Cahill, 1929 – 2008, was a cartographer, philanthropist, chemist, and more.
In the back and front of book 7, it contains an anagram that reads: "GRACE CAHILL = MADRIGAL LEADER"
Grace Cahill was born in 1929 to Edith and James Cahill. She had two siblings: Beatrice, and Fiske Cahill. She went to school in New England, and went to college at Radcliffe College, where she earned degrees in anthropology and chemistry. Grace graduted in 1950. She is known to have a hideout in Madagascar, which the other branches seemed anxious to find, most probably because they thought it might have stolen clues or extra objects of importance to the clue hunt. She married Nathaniel Hartford in 1959, and their daughter, Hope, was born in 1960. Hope then married Arthur Trent, who was a Vesper.
Clues known to haveEdit
Myrrh (confirmed in Book 4)
Salt (as it was found in the Salt Tower in London, she thought that was too easy so it may have been something else)
(According to Card Pack 2 she was desperatly close to getting all 39 Clues)
- Grace Cahill traveled all around the world, exploring every continent. She left no place on Earth unseen.