The film starts with a 12-year-old girl whose babysitter is on a date with serial killer Patrick Bateman. After Bateman kills and starts to dissect her babysitter, the girl stabs him with an ice pick. Fast forward to the present day and the girl, who is named Rachael Newman, is now a college student studying criminology under Professor Starkman, a former FBI agent. Rachael aspires to join the FBI and is determined to get the teaching assistant position under Starkman, which would make her a shoo-in for the FBI training program.Tough competition for the position stands in her way, and Rachael proceeds to kill off classmates one by one. During her killing spree, she decides to see the school psychiatrist, Dr. Eric Daniels. Realizing that Rachael is a textbook sociopath, Daniels tries to warn Starkman, who mistakenly thinks the psycho student is Cassandra Blaire, with whom he had an extramarital affair. When Cassandra reveals that her affair with Professor Starkman has guaranteed her the TA position, Rachael decides to murder her as well. After she does so, Professor Starkman discovers Cassandra's body and calls Daniels to tell him that "she's dead". But he does not identify the victim, and Daniels assumes it must be Rachael. Distraught, Professor Starkman leaves his teaching position, which angers the obsessed Rachael. She reveals that she is not Rachael Newman; she killed the real Rachael at the beginning of the semester and assumed her identity.During spring break, Rachael stays on campus and confronts Starkman, who had taken Valium and alcohol, and tries to seduce him to get the job. However, Starkman sees she is wearing a dress and necklace he had given to Cassandra. She then confesses her crimes to him, her "crush" on him, and that she knew about his affairs with various women (which included her former babysitter, whom he indirectly killed, since he had told her about Bateman and she decided to track him down), as he backs up towards the window in a state of confusion and fear. Rachael blows him a kiss, and he falls out the window to his death. As she leaves, Rachael realizes a janitor has witnessed Starkman's death, and she murders the janitor, too. Driving away from campus with Starkman in her car, Rachael is stopped by campus security, whom she stabs to death with an ice pick.As the film reaches its conclusion, Daniels and two cops pursue Rachael in a car chase, started when she sped by the cops who had Daniels in the car. It ends with Rachael driving off a cliff, resulting in the car exploding. At this point, she is presumed to be dead by the cops who witnessed the event and the media.Two years later, Dr. Daniels is giving a lecture on Rachael's mind and how he wrote a book about her. When he looks up from speaking with a student, he sees Rachael, who has not died after all; she indirectly reveals that she killed Starkman's last assistant, Elizabeth McGuire, and stole her identity to get into Quantico. She allows Dr. Daniels to know because she believes there is no point in committing the perfect crime if no one knows about it and that she is proud of his success. The body that was in the car was the real Rachael. As she walks out of his class, Dr. Daniels is obviously disturbed and rattled.
Output: Question: Who was she studying under?, Answer: Professor Starkman