Maria Martinez is an engineering contractor working for HydralCorp, an international energy company.
Maria was working on a project in Iraq and was travelling in a convoy shipping six generators from Kuwait with her translator, Omar Risha. They were ambushed by terrorists and Omar saved her life. The generators were then requested to be shipped elsewhere by HydralCorp CEO Ken Davis. Maria continued her work with HydralCorp but Omar decided to leave Iraq due to increased terrorism and because he was receiving numerous death threats. Over the course of their partnership, Omar and Maria became lovers and make plans to come to the USA to get married. Omar, however, is framed as a terrorist once he found out about the missing generators. Maria planned to do all that she could to clear his name, even if it meant risking her life.
Davis uses his connections with the United Nations and learns that Maria is trying to prove Omar innocent - he plans to kill her and she therefore becomes a person of interest. Shaw watches her review a generator in a factory and Davis comes over to compliment her work. She gets a call from Omar's brother Jamal, who tells her to meet at "the usual place". She grabs a GPS tracker before leaving.
Maria talks with Jamal, who gives her an envelope. Reese, who is sitting with Shaw at a nearby table, thinks that the envelope contains a bomb, and Shaw follows Maria. She sees Maria taking pictures of French UN diplomat Rene LaPointe, and Maria places the GPS tracker on his car.
Maria follows LaPointe to a party and confronts him with proof that Omar is innocent. LaPointe asks security to escort her out but Maria is met by Greek diplomat Christos Sevon, who offers his help. She thanks him and leaves.
That night, Maria is heading home and Shaw follows her. A man opens the door for her and gets in the elevator with her, but Shaw enters just as the doors close. The man is an assassin from the French Foreign Legion and Shaw takes him down. More assassins appear in the hallway upstairs, but Fusco is waiting to assist Shaw. Reese charges from the stairwell and tackles one of the assassins out of the window landing on top of him on a car parked several floors below.
Maria is taken to a safe house and greeted by Finch, to whom she explains her situation,omitting the part about she and Omar being lovers. Finch hands her a letter from the Iraqi Ministry of the Interior implicating Omar as a terrorist and he figures that LaPointe is involved in the attack as he has connections with French Legionnaires. Reese suggests that Finch pose as Omar's lawyer, and they leave while Shaw stays with Maria.
Maria and Shaw compare Omar's recommendation letter from Davis as well as the paperwork framing him as a terrorist, and notice similarities in wording and formatting - they discover that Davis forged the paper naming Omar a terrorist and Maria realizes that the original papers are in LaPointe's office. She becomes desperate to go but Shaw insists she stay for her own safety.
Maria tells Shaw she could use a drink - Shaw agrees and goes to get one, but Maria overloads the generator on the electromagnetic door lock and escapes, trapping Shaw in the safe house in the process.
Maria heads to the UN building and begs the guard to allow her in, but he refuses. Sevon notices her and gets her permission to enter with him. Maria says she wants to get into LaPointe's office, and while Sevon considers the plan dangerous, he agrees to get Maria that far. Inside the office, Maria goes through LaPointe's paperwork and finds the document about Omar, but LaPointe suddenly walks in. Sevon apologizes for the confusion, revealing himself to be working with Davis, and shoots LaPointe dead. He is about to kill Maria when Reese and Fusco come in. He surrenders but suddenly attacks Fusco who punches him. Maria knocks out Sevon with a ceramic bowl. She happily reunites with Omar, who Reese rescued earlier and brought with him.
Later that night, Maria and Omar sit at a restaurant with a memorable view of the New York City skyline, and Fusco informs them that Omar's request for political asylum has been approved. He also tells them that Sevon's diplomatic immunity has been revoked and he has been arrested for the murder of LaPointe. Maria and Omar admire the view and kiss. (“Allegiance”)