At the start of the novel, Tom Ripley is pacing the streets of New York. He senses that someone is following and becomes nervous, as he fears the man is a policeman, come to arrest his for his numerous acts of forgery and impersonation. Here we learn that Tom is an experienced conman and fraudster who struggles financially and desires for a better life. The man approaches Tom and introduces himself as Herbert Greenleaf, the father of Dickie Greenleaf. Tom tries very hard to remember, and vaguely recalls Dickie - "a tall blonde fellow [with] quite a bit of money." Herbert persuades Tom to go to Italy and bring Dickie home. He offers to pay Tom money, so Tom accepts.
The chapter begins with Tom travelling to Italy. On the ship to Europe, Tom writes a letter to his aunt. We find out that Tom has been raised by his aunt after his parents die, and that the tom then kills himself so he can eat chips
Tom and Dickie become closer. At the beginning of the chapter, Dickie wants to show Tom his paintings. Tom is very enthusiastic and praises his skill, which gets him on Dickie's side. To show his appreciation, Dickie invites Tom to move in with him for a short while, just while he stays in Mongibello. Tom and Dickie then prepare to go to Naples for a short trip. On the way, they meet Freddie Miles, a god friend of Dickie's. Tom took an immediate dislike to Freddie. When they arrive back in Mongibello, Marge is annoyed that Dickie didn't tell her they would be going away for the night. She doesn't speak to Dickie for a few days. Tom suspects that Marge loves Dickie, and he takes her for granted. To make up for his absence and lack of consideration, Dickie and Marge go away for a short while. In this time, Tom feels neglected and ignored. He goes to Dickie's room and tries on his clothes. Dickie walks in on him in his clothes and tells Tom off. Tom is extremely embarrassed.
Tom gets a letter from Herbert Greenleaf. He is angry that Dickie hasn't come home yet, since it has been one month since he sent Tom to Italy. Herbert says that he will no longer be paying Tom to stay in Italy.
Tom and Dickie plan to go to San Remo. They invite Marge but she turns down the invitation, as she is working on her novel. The train ride to San Remo was very tense. Tom feared this would be the last time he would do anything with Dickie, and felt uncomfortable with Dickie's constant silence. Tom decides, for no apparent reason, that he wants to kill Dickie. He confesses that this thought has crossed his mind many times. "He wanted to kill Dickie. It was not the first time he had thought of it. Before, once or twice or three times, it had been a desire that went away immediately and left him with a feeling of shame." Tom then hatches a plan to kill Dickie and then "become him", taking on his identity in order to live his life of luxury. Tom considers a range of ways to kill Dickie, but dismisses them all as too difficult. Dickie takes Tom on a private boat ride, and Tom uses this time to brutally beat Dickie and bury his body in the ocean. Tom then returns to Mongibello and tells Tom that Dickie ran away and wants to live his life in Rome, thus abandoning her.
Tom continues his plan. He moves to Rome and sends Marge a hand-written letter, pretending ot be Dickie. In the letter, he tells Marge that he wants to leave her and live in Rome. This confirms the false story that Tom told her.
Complications arise when Freddie comes to find Dickie. As he talks to Tom, he quickly notices that Tom is wearing Dickie's clothes and jewelry. He becomes suspicious, and challenges Tom. Tom fears that Freddie will expose him for murder, so he kills Freddie and dumps his body in the woods. This is now Tom's second impulsive, irrational murder.
Police visit Tom to inquire about Freddie's disappearance. The police believe that Tom is Dickie. They question him about what Freddie was doing the day he was killed, and tell Tom not to leave, as he is needed for further questioning. Later, police officers appear and ask him where Tom Ripley is. Tom says that Tom Ripley is now in America.
Tom becomes extremely paranoid and is certain that he will be discovered for the two murders. Marge comes to the hotel where Tom is and asks if he knows where Dickie is. Tom says that Dickie is at the police station for questioning. Tom (pretending to be Dickie again) picks up Dickie's mail. He sees that Marge has replied to the letter he sent, and that she accepts their relationship is over, will be moving out of Italy, and doesn't want to hear from him again. Tom then flees to Sicily to avoid being caught for murder.
While in Sicily, Tom receives a letter addressed to Dickie. It is from the police, who are summoning Dickie to Rome to answer questions about Tom Ripley. Tom decides to flee. First, he sends Dickie's valuable possessions to Venice under the false name Robert S. Fanshaw, hoping that he could then pick them up when things calmed down. Tom comes across a poster that indicates that police think Dickie Greenleaf is running from the law. Tom is relieved, as this means that police are less likely to focus on him.
Tom goes to Venice and identifies himself to the police as Thomas Ripley, using his real passport to prove his true identity. The police officer tells Tom that he needs to speak to the police in Rome. Tom tells the officer that he doesn't want to go to Rome, so the Roman police officers come to meet Tom in Venice. One of the officers is the same officer who interrogated Tom (pretending to be Dickie) in Rome, but does not recognize him as the same person. The police do not suspect Tom, and Tom feels extremely relieved.
Tom then forges a note from Dickie, saying that he leaves large amounts of money to Tom in his will. This way, Tom will become rich.
Tom writes letters to Herbert Greenleaf and Marge, suggesting that Dickie killed himself, thus explaining his absence. Marge writes back, saying that she doubts Dickie committed suicide. Days later, Marge arrives unexpectedly in Venice. She is still doubtful that Dickie killed himself, as she found that he cashed a cheque for a few thousand dollars days before his disappearance. Tom invites Marge to stay with her, in order to avoid suspicion. Tom thinks about how he deeply despises Marge, as she has been intimate with Dickie. This suggests that Tom is jealous of Marge.
Herbert Greenleaf arrives in Venice and meets with Tom and Marge. The meeting goes well. Mr Greenleaf tells Tom that he has discovered reports of his previous fraud charges, but promises to keep them secret. Tom is relieved.
After Tom constantly persuades them, Marge and Mr Greenleaf begin to believe that Dickie may have committed suicide. Furthermore, police believe that Dickie is in hiding, and that Dickie killed Freddie. Tom is relieved as he no longer thinks he will be exposed for murder. Herbert Greenleaf announces that he will be leaving Venice, as he is no longer able to find any useful information.
Tom writes to Mr Greenleaf, saying that he has found Dickie's will. Tom considers how bull shit it was to forge Dickie's will, but is excited at the prospect of becoming rich. Tom finds out that police have found Dickie's items left in the fake name and intend to scan them for fingerprints. Tom fears this will expose him as Dickie's killer.
Tom flees to Greece. There, he sees a lot of police officers. He walks straight past them and they do not notice it - he interprets this as a sign that he is no longer under suspicion.
In another turn of good luck, Tom gets a letter from Herbert Greenleaf saying that he will honor the will. Furthermore, official papers indicate that police are ruling that Dickie committed suicide. Tom is relieved - "Tom reveals himself. It meant that he was not going to jail, and not going to die, but also that he wasn't suspected at all. He was free."