Gloria Nathan is a doctor featured in Oz. Portrayed by Lauren Velez.
Dr. Gloria Nathan is the Chief Attending Physician of Oz. A good person, she deals with conflict all the time, whether it is from the inmates such as Ryan O'Reily, or state medical boards. She manages to come out calmly throughout any conflict.
Dr. Nathan is Oz's chief physician who does her job with as much compassion and fairness as possible. She's close to Sister Peter Marie and she often seeks her advice on many of the patients. She has a good working relationship with her fellow staff, but Emerald City Unit Manager Tim McManus decides he wants more from her. She's open to the suggestion because her marriage is crumbling at home, and the two of them engage in a few dates. When Tim exhibits aggressive behavior, she backs off.
Dr. Nathan diagnoses Ryan O'Reily as having a cancerous tumor in his breast, and then lobbies for its removal, instead of just a lumpectomy. Leo Glynn refuses and approves the lumpectomy for budget reasons. Ryan pulls through, but while recovering, he falls in love with the doctor, causing her much stress and confusion. She passes his inamorata off as a phase but soon realizes it has grown into a dangerous obsession. Her husband is murdered and she soon finds out it was Cyril, Ryan's brother, who did the deed. Disgusted and filled with anger, she confronts Ryan.
Appalled that the new hospital administrator eliminated Miguel Alvarez's medication to cut costs, Dr. Nathan fights back by contacting the press. Even though the administrator fired her, the Governor appeals for her not to talk to the press in exchange for her job back and he promises to "handle" the administrator. She gets her job back and the administrator is forced out.
Dr. Nathan decides to participate in Sister Peter Marie's victim offender counseling program which requires she and her in-laws to face Cyril and Ryan. Her dilemma is she has to work in Oz always knowing that Ryan gave the order to Cyril to commit the murder. During the session, her in-laws express their feelings. The session escalates when Cyril starts crying while apologizing for killing her husband. Gloria's anger ensues and Ryan responds by professing his "never ending" love for Gloria, something she doesn't understand. This adds to her torment. One evening on her way home, Gloria is attacked and raped. Although she returns to work quickly, she soon realizes that she needs more time to recover so she takes an indefinite leave from Oz.
Dr. Nathan returns to Oz after taking some time to recover from her attack. This time, the Wygert corporation decides to test an experimental drug on the inmates that would allow them to age faster. Although she's morally against it, she administers the drug to willing inmates--two of which are Cyril and Ryan O'Reily. To make matters worse, Ryan O'Reily constantly reminds her of how much he loves her. She confronts him about Keenan's death (the inmate who raped her, whom O'Reily killed in the gym)) and he admits to doing it. All this confuses her and she confesses to Sister Pete that she thinks she may actually be in love with Ryan. Sister Pete warns her that his love is not unconditional and that she should be very careful. Back to the experimental drug project, after Aryan inmate Fred Wick, who was taking the drug dies, the project is halted. Dr. Nathan gets word from the prison authority that she will be investigated for her part in the program and her mishandling of the drugs causing the experiment to fail. For this, she could lose her job when all she was doing was following instructions.
Dr. Nathan has a flashback to her rape while examining Carlos Martinez in solitary. Martinez kept touching her in a sexually suggestive manner and she kept telling him to stop. When he didn't stop, she became enraged and started beating him. After this incident, she immediately went to Sister Peter Marie to discuss how this happened. She can't understand why she would attack a patient so violently. Sister Pete understands Dr. Nathan's feelings and explains that Dr. Nathan's actions were a means to act out her anger. She further suggests Dr. Nathan contemplate exactly why she continues to work at Oz after all that's happened to her. Later, Dr. Nathan also begins to reveal more compassion for Cyril O'Reily plight when he gets brought up on murder charges. When Chucky Pancamo arrives to the infirmary after being shanked by James Robson, she treats him for the wound only, it gets infected and his condition worsens. Dr. Nathan now feels responsible for this and she's conflicted again. After talking with McManus, she dedicates herself to getting Pancamo better.
The deaths of Hispanic inmates Enrique Morales and Carlos Martinez make Dr. Nathan suspicious of who or what is causing the inmates to perish. When it turns out both men were suffocated, Warden Glynn recalls Morales telling him to investigate nurse Carol Grace's background. Upon investigation, it is found that other patients at previous hospitals died as a result of her. When confronted by police, Grace tries to run but is quickly caught. Grace insults Dr. Nathan with racial slurs as the police take her away. Dr. Nathan doesn't want to cover up the deaths of inmates as a result of poor care anymore, so she documents the information at Glynn's objection. She then feels guilty about this after his death. She later informs James Robson that he is HIV positive. Robson has her swear not to release the information to any personnel or inmates.
Once Seamus O'Reily ends up in the infirmary, Ryan plots to kill him, however, Dr. Nathan convinces him to forgive his father, as once his brother is gone, he'll be needed even more by his father's side. Dr. Nathan confronts Ryan O'Reily in the gym while he is walking the meditation maze during Cyril O'Reily's execution. After years of the back-and-forth feelings she and Ryan have had for each other, she finally embraces and kisses Ryan passionately, to which he responds in kind.
After a mysterious package shows up in the mailroom and kills all the Aryans (and two COs), she lets the new Warden, Martin Querns know that the entire prison is now at risk, to which he orders an evacuation of the entire prison. Dr. Nathan is last seen boarding one of the buses that escorts everyone away from OZ.