|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 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).
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.
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.
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.