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The Outcast
Branch:Ekaterina, Madrigal
Age:89-91 (Series 4)
Relationships:Grace Cahill (wife) Hope Cahill, Amy Cahill, Dan Cahill
First Appears In:Mission Titanic
Last Appears In:Mission Atomic
The Outcast (known by his real name as Nathaniel Hartford) is a former member of the Ekaterina branch, and the main antagonist of the Doublecross series. He is trying to gain leadership of the entire Cahill family. He thinks that the leaders of the Cahill family (Ian Kabra and Cara Pierce) are too young, so he sets up a competition where the young Cahills have to stop a series of four disasters from happening.


Pre-Mission Titanic

The Outcast was banned from the Ekat branch many years ago, so he is trying to get his revenge. He recruits Aleksander Spasky (Lucian), Magnus Hansen (Tomas), Melinda Toth (Lucian), Toby Griffon (Janus), Vikram Kabra (Lucian) and Patricia Oh (Ekaterina).

Mission Titanic

He infiltrates a Cahill family meeting, and stages a mutiny against Ian Kabra and Cara Pierce. He gives the young Cahills a riddle to solve, and that riddle eventually leads the young Cahills to correctly believe that the Outcast is trying to recreate the Titanic disaster.

Mission Hindenburg

He travels to Florida where he neutralizes Beatrice Cahill. He also gives the Cahills a riddle to solve regarding the Hindenburg air disaster in 1937. Nellie Gomez and Sammy Mourad later find information that proves the Outcast to be Grace Cahill's husband, Nathaniel Hartford.

Mission Hurricane

Mission Atomic

It is discovered that he caused the Chernobyl disaster to happen.


In the end of Mission Atomic, the killer bees Nathaniel develops to wipe out the Cahills cover him up and sting him. As he is a Cahill, he dies.