The plot follows a creative writingstudent from Suffolk named Tim Cornish, an exceptional student who leads a promiscuous lifestyle. A series of chance meetings with Dr. Ivo Steadman, a lecturer at Tim's University, leads to a relationship between Tim and Ivo. All goes well until Ivo expresses direct love for Tim. Haunted by such admissions from his suitors at school, Tim is driven cold and amuses himself with a chance sexual encounter when Ivo is busy with university work. He taunts Ivo who throws a punch at him in consequence. Despite his reservations about Ivo's behaviour, Tim agrees to accompany him to Alaska. Before the trip, Ivo buys supplies for them, including a distinctive yellow coat for Tim. Once they arrive in Alaska, complications arise which lead to Ivo postponing the trip while he supervises a cruise, leaving a reluctant Tim in their hotel. Tim then meets and becomes infatuated with a woman named Isabel, and they have a brief affair. When Ivo returns, he is met with an unenthusiastic Tim, who is still in love with Isabel and is growing impatient with Ivo. They then journey by boat to a remote island. The journey, during which Ivo rapes Tim, is made even more turbulent by Ivo's suspicions that Tim has had an affair. One night on the cruise, while Ivo muses about where they should travel next, Tim tells him that he wants to leave him. Ivo is shocked and doesn't believe Tim knows what he wants. Tim tells him in no uncertain terms that he does not love Ivo and never has, that he is in love with Isabel and as soon as the cruise is over, he is going to leave to be with her. Ivo becomes so enraged that he throws Tim on the bed and starts to choke him. Tim throws him off but it is understood that Ivo wouldn't have stopped otherwise. The next morning, a group of people travel to a remote island to study fossils. While the rest of the group wanders the island, Ivo and Tim have a heated argument about the affair. Before Ivo has a chance to leave, Tim reveals that he would have left Ivo long ago if it wasn't for Isabel, that she was the only reason he stayed. This drives Ivo into a rage, and in the ensuing fight, Tim accidentally throws him against a rocky mountainside, leaving him unconscious. Believing he has killed Ivo, Tim manages to flee to Vancouver, British Columbia, without creating any suspicion. There he unsuccessfully searches for Isabel before returning to the United Kingdom in defeat. During his search, he starts a sexual relationship with a homeless drifter, Thierry. Tim buys expensive items for Thierry with Ivo's credit card, giving Thierry the impression that Tim is rich. Ivo, who was not actually killed, has escaped from the island where Tim left him and confronts Isabel about the affair. Ivo then reveals that, unbeknownst to Tim, Isabel is actually his sister who had been asked to keep an eye on Tim's behaviour while Ivo was away supervising the cruise, explaining his earlier anger. Soon Tim begins to receive anonymous letters, making it clear that someone is aware of his crime. Thierry shows up at Tim's house and though he tries to rekindle their affair, Tim has lost interest and it is clear Thierry hopes to rob Tim. Eventually, he leaves when Tim tells him the money he spent on him earlier was not actually his and he is not rich. Eventually, Ivo turns up in person at Tim's house and discusses the previous events with him. When he leaves, Tim gives him the yellow coat. Ironically, on leaving Tim's house, Ivo is murdered by Thierry, who had mistaken Ivo, cloaked in Tim's coat, for Tim himself. In contrast to the end of the novel, which suggested Isabel and Tim could rekindle their relationship, the film's closing scene shows Tim unable to open his door and let Isabel into his house, overwhelmed by the fear that his destructive influence might reach even to her.
