|Age:||79 (Series One, deceased)|
|Relationships:||The Cahill Family|
|First Appears In:||The Maze of Bones|
|Last Appears In:||Day of Doom|
Grace Madeleine Cahill was the leader of the Madrigal branch of the Cahill family, a very rich lady, cartographer and frequent aviator in her private plane, the Flying Lemur. Depending on who you asked, she was one of the most loved or hated members of the family. Her death in 2008 was the starting point of a chain of events to find the 39 Clues.
Grace was the daughter of Edith Green, and James Cahill, the younger sister of Beatrice Cahill, the older sister of Fiske Cahill. She became an avid aviator, flying the Flying Lemur, her own private plane around the world collecting map data in unexplored lands, and mapping them, creating some globes of the world, one she autographed and put in the secret library of her mansion. Grace had a daughter, Hope Cahill with Nathaniel Hartford.
In 1985 Anne Cahill gave Grace an Ekaterina Clue, Phosphorus, to fly to Scotland in resentment of her branch. Grace took the Flying Lemur and briefly landed at a Scottish tarmac. She was contacted by Simon and Jim as she flew, who were air traffic controllers. Grace was flying over Loch Ness when her plane was attacked by the Ekats, and it began to fall in Loch Ness, but Grace was able to survive. She went to Anne's 'grave', and made a map of the plane crash. She sent a letter to Anne detailing the misfortune.
Hope Cahill died in a fire with Arthur Trent, her husband. She had a week-long winter holiday with other members of the Cahill family. She saw her grandchildren, Amy Cahill, and Dan Cahill every weekend after pressuring Beatrice in becoming their legal guardian. Once she found a young Dan with an Aztec dagger he stole from her display case and told him about it instead of scolding him. She'd have picnics with Amy, telling her about the Ekaterina, Janus, Tomas, and Lucian branches. Grace didn't permit Attleboro workers to look in her lab, and got sued. However, her lawyer William McIntyre convinced the jury to rule in her favor over Attelboro.
She later contracted terminal skin cancer, and the last time she saw Dan and Amy, she told Amy that she'll make her proud. Five minutes before she died with Saladin on her lap she decided to use her alternate will, William McIntyre warning her of the outcome. Grace then passed away. Her body was put outside her mansion.
- Rebbeca Schnieder - Maternal Grandmother (deceased)
- Eijah Green - Maternal Grandfather (deceased)
- Flora Cahill St. James - Paternal Grandmother (deceased)
- Henry Cahill - Paternal Grandfather (deceased)
- Hae-In Oh - Paternal Step-grandmother (deceased)
- Bae Oh - Paternal Uncle
- Gordon Oh - Paternal Uncle (deceased)
- Lin Kim - Paternal Aunt-in-Law (deceased)
- Alistair Oh - Paternal Cousin (deceased)
- James Cahill - Father (deceased)
- Edith Cahill - Mother (deceased)
- Beatrice Cahill - Sister (deceased)
- Stephano Breglio - Divorced Brother-in-Law (deceased)
- Jean-Luc Benoit - Divorced Brother-in-Law
- Sergei Baskov - Divorced Brother-in-Law (deceased)
- Fiske Cahill - Brother
- Nathaniel Hartford - Husband (deceased)
- Hope Cahill - Daughter (deceased)
- Arthur Trent - Son-in-Law (deceased)
- Amy Cahill - Granddaughter
- Dan Cahill - Grandson
Grace Cahill changes her will during the last five minutes of her life. This new will set the "official" Clue hunt in motion. She then dies 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 realizes it's missing.
Eight months before the Clue Hunt began durning the Christmas season, Grace learns that she had cancer. She had thought the Vespers disappeared--but an attemped Vesper attack on Amy and Dan Cahill force her to use the alternate will to start the 39 Clues hunt and called Professor Astrid Rosenbloom.
- She can fly a plane. Her plane is called "The Flying Lemur."
- She is very good at security.
- She is very wealthy.
- She is a multilinguist; she can speak 12 languages fluently.
- She knows how to use any weapon from a rifle to a boomerang, with which she is unrivaled.
- She is a talented cartographer and managed to make her own globe using the knowledge she collected during her travels.
- She can use a dart-gun.
- Apparently, she came close to assembling the 39 Clues but did not succeed in collecting all of them.
- Landing Private Jets in her front yard.
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 = 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 have
- Salt (as it was found in the Salt Tower in London, she thought that was too easy so it may have been something else)
- Iron solute (As shown in Book 1)
According to Card Pack 2, she was desperately close to getting all 39 Clues.
- Grace Cahill traveled all around the world, exploring every continent. She left no place on Earth unseen.
- Grace had a plane named the Flying Lemur.