Dr. Ronald W. Carmichael is a psychiatrist, and was treating Root at Stoneridge hospital.
Carmichael tries to understand what Root means by the voices she claims to be hearing, but she continues giving him cryptic answers that he finds unusual. He later finds a phone in her pocket and tells the workers at the facility to lock up Root in solitary confinement with no contact with anything electronic. She tells him it's not good for her to be separated from "it".
Root is later brought into Carmichael's office because he wants to really know what she's talking about. When she asks what they are going to talk about, he says that they should discuss the truth. Smiling, Root begins telling Carmichael that the truth is a very vast thing, and that he is only the 43rd smartest person in the building. She then goes on to reveal to Carmichael that she knows about how he cheated on his medical exam, his habit of smoking in the parking lot about nine cigars a week, how he pays for a monthly massage therapy using money stolen from a 7/11 cash machine, and how he spends time on online forums fantasizing about having sex with his patients. As he listens in shock, Root says that god was created 11 years ago, referring to the Machine, and that she's actually scared of what will happen. She then says that they are arguing about whether or not she'll kill him. The Machine then calculates the probability of his death, and awaits results. (“Liberty”)
Still alive, Carmichael acknowledges Root's ability to learn the truth about him, and finally begins to accept that there may be some kind of "voice" she's hearing from. Root tells him that it's finally time to escape into a "transcendence of reality", and that the Machine has a plan.
Root, who has been planning her escape for a while, explains her plan to a visibly nervous Carmichael. She tells him that a government operative is coming to kill her and goes through the procedure of the rest of the escape. The phone on Carmichael's desk then rings, and Root walks into a hallway full of unconscious guards. She picks up an earpiece and a gun, and begins shooting at Hersh, who has arrived. A terrified Carmichael watches Root shoot down Hersh and walk away. Harold Finch arrives at the hospital and finds Carmichael tottering away from the bodies, including an unconscious Hersh. (“Lady Killer”)
- Carmichael knows Root as Robin Farrow.
- Root's belief that Carmichael is the 43rd smartest person in the building is based on the average of all his standardized test scores. In actuality, there are several problems with her mathematics, and the assumption that she is able to calculate intelligence by averaging standardized scores: standardized tests are designed to measure a variety of things, from intelligence and academic achievement to potential success in higher education, such as Carmichael's medical boards.