On this week's Person of Interest...

Root continues to follow the Machine's orders. She is assigned to retrieve a janitor who has access to a secure room that houses the computer chip to put the other machine, Samaritan, online.

Reese, Finch and Shaw receive a number for the janitor. They try and keep him alive, while teaming up with Root.

Root learns that back when she was just an assassin for hire, she killed the janitor's former workers.

Decima and Vigilance descend on the team trying to get to the janitor and the computer chip.

Shaw manages to fight off vigilance.

Root, after some persuasion from Finch and new hardwiring to the Machine, chooses to save the janitor.

Decima retrieves the computer chip.

Root chooses to depart rather than stay with the POI team.