Plot
In 1990, Susan Morrow is surprised to hear from her ex-husband, Edward, who sends her a manuscript to his novel, Nocturnal Animals. Susan and Edward's relationship had fallen apart 25 years earlier in part thanks to him abandoning his studies to be a lawyer to pursue a writing career. After putting off the manuscript for months, she reads it in the course of three nights after learning that Edward will be passing through her city soon.
Nocturnal Animals is about a meek mathematician named Tony Hastings on his way to his country home in Maine with his wife, Laura, and teenage daughter, Helen. On the way, they are accosted by three men in a truck, Ray, Lou, and Turk, who begin blocking the path to their car. The cars end up bumping each other and the leader of the men, Ray, gets in the car with Laura and Helen and drives off with them. Ray drives Tony to a clearing and abandons him there. Tony walks to a farmhouse he manages to call for help. In retracing his steps with the state troopers, he discovers Laura and Helen, both raped and murdered, in the clearing where he had been abandoned. He blames himself for not doing enough to save them.
For a year after the murders, Tony falls into depression. The lead detective on the case, Bobby Andes, calls him in to identify a possible suspect, but when Tony cannot positively identify a man who turns out to be Turk, Andes seems to lose interest in the case. Sometime later, Andes again calls Tony to I.D. a man and this time he is able to identify Lou as one of the men who murdered his wife and daughter. He learns that all three men had been involved in a robbery and that Turk was shot to death. Andes brings Tony with him to pick up and identify Ray and, after Tony makes a positive I.D., Andes takes them on a trip to the scenes of the crime. Though Ray denies any knowledge of the crime, Tony feels he is mocking him and at one point is overcome with rage and hits him in the face.
Tony at last starts to move on with his life and begins a relationship with one of his former graduate students. He receives a call from Andes telling him that Ray is about to be set free. He goes to meet Andes, who tells him he has cancer and six months to live. Andes then asks him if he wants to see Ray brought to justice. Sensing Tony's tacit approval, Andes arrests Ray and brings him to a remote camper in the woods where his ex-wife Ingrid is staying, unbeknownst to Andes. They are later joined by Susan, Andes' cousin. Andes goes and retrieves Lou from the jail. In the camper, Andes threatens to torture both Lou and Ray, but they run away. As a result, Andes shoots and kills Lou while urging Tony to do the same to Ray. Tony cannot bring himself to commit murder, however, and allows Ray to escape. Andes tells Tony and the women that if they are questioned they must say that Ray killed Lou.
Andes has Tony go to send a message to one of his police friends. Along the way, Tony passes Ray walking along the side of the road and later goes to the trailer where Helen and Laura had been raped. He finds Ray sleeping there. He wakes Ray up, and they have a conversation in which Ray confesses to raping and murdering Laura and Helen. Tony then shoots and kills him, but is blinded and badly wounded in the process. He stumbles out of the trailer and falls down a ravine. He hears the police coming to save him, but he does not call out to them, instead accidentally shooting himself in the gut. As he dies, he hallucinates driving to Maine with Helen and Laura.
The novel causes Susan to reminisce about her past life with Edward. They were neighbors who briefly lived together after Edward's father died and her parents took him in. They met again in college, and slept together despite Edward's puritanical views on sex. However, a short time into their relationship, Edward decided that he wanted to be a writer and that the two would survive on Susan's income as a lecturer. After Edward left for a month-long writer's retreat, Susan began an affair with their neighbor Arnold, whose wife was experiencing mental breakdowns. Sometime after Edward returned, Susan confessed all of this to Edward and eventually divorced him, settling down with Arnold and tolerating his affairs.
Susan enjoys Edward's novel and finds herself sympathizing with Tony. She decides to invite Edward over for dinner the night he is in town in order to discuss his work. Edward never calls, despite the fact that Susan leaves several messages at his hotel. The following day, having discovered he has checked out, she writes a thoughtful piece of criticism for him and then throws it away, sending him a brief note instead telling him she will give him her thoughts if he would like them.
