Patrick Bateman has two distinct sides: the outer, surface self—well-dressed, materialistic, and successful—and the inner self—filled with violent impulses and insecurity. His narrative includes meticulous detail about designer clothing and accessories, his morning grooming regimen, his trendy and expensive health club, and the exclusive restaurants and clubs he frequents. Long lists filled with brand names and the minutia of his daily routine fill pages and pages of the novel. But recounted in the same tone, and often interspersed with this relentless everyday detail, are his violent actions/hallucinations. As Bateman's narrative continues, his grasp on reality—tenuous to begin with—deteriorates. Whole days are spent hallucinating. His violent tendencies also accelerate and intensify. He begins saving body parts for later and even becomes cannibalistic. He kills people in public. Then he goes on a shooting spree through the streets of New York, after which he leaves a confessional message on his lawyer's answering machine. Despite this dramatic climax to his narrative, he returns to his routine shortly afterward. This leaves the reader to wonder whether his violent acts were real or part of his hallucinatory alternate reality.
As the novel opens, Evelyn Richards is hosting a dinner party, to which she has invited both her yuppie and her artistic friends. She is attempting to arrange sushi on a platter and is unsatisfied and anxious about whether the arrangement looks right. She also worries the sushi is not an adequate replacement for eating out at one of the many upscale restaurants she and her friends typically frequent. Evelyn shows a similar level of social anxiety at her Christmas party, focused particularly on the Waldorf salad. Her relationship with Bateman is unexciting. Though they continue it, Bateman is also seeing Evelyn's friend Courtney Lawrence, and there are hints that Evelyn is also not completely faithful. Eventually, Bateman becomes tired of maintaining the relationship and cruelly tricks Evelyn into eating a urinal cake, citing its minty flavor.
Courtney Lawrence is one of Evelyn's close friends and is dating Luis Carruthers. She and Carruthers are frequently among the group that is out on the town with Bateman, Evelyn, and other friends. She is a pill popper and typically zoned out on various prescription drugs. She and Bateman are having an affair. Eventually Courtney marries Carruthers despite Carruthers being secretly gay or bisexual.
When Jean is first introduced, Patrick Bateman says she is in love with him. This comment may seem like Bateman's own arrogance since he often suggests that other women he encounters are also in love with him. Yet Jean does go over and above to please him at work even though he is frequently short-tempered and demanding. Later in the novel, Jean and Bateman develop a friendship of sorts, even going out for dinner. However, while Jean continues to seem interested in pursuing a more romantic relationship with Bateman, he consistently rejects her attempts to get closer to him. Unlike many of the other women in the novel, Jean seems interested in Bateman as a person, not just a social or sexual partner.
From the beginning of the novel, Patrick Bateman is obsessed with Paul Owen and the Fisher account. Since the two men have a similar social life, they often run into each other at clubs and restaurants. Owen consistently mistakes Bateman for Marcus Halberstam, an error Bateman never corrects. The killing, whether real or imagined, of Paul Owen seems well-planned. This suggests that Bateman's dislike and jealousy of Owen comes to a head before the night of the killing—in time for Bateman to prepare. After the murder, Bateman records a fake answering machine greeting suggesting Owen simply went to England on vacation. His ploy seems successful. Though there appears to be an investigation into the disappearance of Owen, there are no real ties to Bateman. As the novel comes to a climax, Bateman confesses the murders, including that of Paul Owen, to his lawyer. However, doubt as to whether Owen is alive or dead arises when his lawyer claims to have met Owen recently. At the end of the novel, there is no closure as to whether the murder of Owen, or any of the other murders, ever actually happened.
Although Luis Carruthers is officially dating Courtney Lawrence, she is having an affair with Bateman behind his back. This prompts Bateman to wonder at one point whether Courtney would like him better if Carruthers were dead. The idea takes hold, and Bateman follows Carruthers into a restroom at a restaurant and prepares to strangle him. However, Carruthers perceives the strangling attempt as a come-on and begins to reciprocate, throwing Bateman off guard. Unable to follow through on the murder, Bateman exits the restroom. From this point on, Carruthers gives Bateman knowing looks and makes it obvious he would welcome a sexual relationship. Bateman's reaction to the revelation that Carruthers is gay, or possibly bisexual, is odd. He wills himself to strangle Carruthers but cannot make his hands obey him. To some readers, this suggests that Bateman may have unacknowledged bisexual desires.