Six is one of the elite agents trained under the Sierra program and was recruited by Donald Fitzroy while serving a sentence in prison.
The Sierra Program was a program in the CIA that recruited hardened criminals from prison and trained them to be elite assassins with no identities. Six was recruited in a similar fashion but why was he in prison to begin with?
Freedom with a price
According to the report read out by Fitzroy, Six was sent to prison at the age of 15 and he had another 28 years there before being eligible for parole.
Fitzroy offers him a chance at getting out but for that, he will have to accept becoming a trained killing machine. He tells Six that since he’s already killed one bad person before, he’ll b up for doing more often.
Fitzroy mentions that he’s studied Six’s case and assures him that he did the right thing by pulling the trigger, adding that he would have done the same thing in that position.
Six often got flashbacks of his traumatic past where his father was physically abusive towards him. While recovering from their encounter with Avik San, Dani asks Six about the reason he went to prison.
Six tells her that his father was an advocate of toxic masculinity and tried to impart his ways to Six and his brother by beating them and “toughening them up”.
Six was afraid that all the abuse would lead to the death of his brother, so he chose to grab a gun and kill his father instead. While he thought what he did was right, the justice system did not and sent him to jail where he stayed until Fitzroy got him out.