Tom decides to rehabilitate his relationship with Dickie. He finds him alone on the beach and invites him to have a drink. Tom takes Dickie to his hotel and gives him the gifts he's brought on behalf of Dickie's parents. He then reveals that he has been sent by Mr. Greenleaf. Dickie is amused, and seems to trust Tom after this display of honesty. He invites Tom to lunch along with Marge, whom he also tells about Mr. Greenleaf's machinations. Tom amuses Dickie by performing an impersonation of a British woman trying to ride the subway, and while Dickie finds this hilarious, Marge is merely perplexed. Dickie then shows Tom his paintings, and Tom concludes that Dickie is an untalented artist. He is disappointed, having expected him to be skilled. Tom asks Dickie to go to Naples with him, and Dickie agrees, assuming that Marge is also invited. In order to exclude Marge, Tom says he would prefer to go during the day, knowing that Marge will be working on the book she is writing. Dickie agrees to go the next day. Tom also invites Dickie to dinner at his hotel, and Dickie again assumes that Marge is also invited. That night, Tom is irritated by Marge's presence at dinner, but disguises it, and Dickie asks Tom to stay at his house rather than a hotel. He moves into a spare room the next morning, and then the men set off for Naples. On the bus, they run into Freddie Miles, an acquaintance of Dickie's. Tom takes a strong and immediate dislike to him. In Naples, Dickie knows many locals and has friendly conversations with them. He then suddenly asks Tom if he would like to go to Rome.
Tom and Dickie hitch a ride to Rome with a stranger and see a music-hall show. Tom notices, while driving around the city with Dickie, how much they look alike. They stay up late and get drunk. When they run into a girl walking by herself, they insist on escorting her home, and congratulate themselves on their kindness. The two fall asleep in a park and are woken by an angry policeman. They travel back to Mongibello, where Marge is angry at Dickie for staying away overnight without telling her, and seems even angrier about the fact that Dickie has clearly had a very good time. Tom revels in her jealousy and dismay, feeling that he now has a closer bond with Dickie. Since he is feeling triumphant, he resolves to be charitable and kind to Marge, but finds her grating. Dickie, meanwhile, claims that Marge's coldness and avoidance is simply a result of her being busy writing. Meanwhile, Tom's life is going well. Dickie has hired him an Italian tutor, Fausto, and his language skills are improving. When not studying, he spends his days on the beach and writes letters to Mr. Greenleaf, hoping that Mr. Greenleaf will send him more spending money. Tom and Dickie make travel plans for the winter in which Marge is not included, and Dickie seems to feel guilty about leaving her out, though Tom tries to convince him not to.
One day Dickie decides to have a private conversation with Marge in Marge's house. Tom peeks in through a window and sees Dickie kissing Marge, to his chagrin. He goes back to Dickie's house and impulsively tries on some of Dickie's clothes in front of the mirror, mimicking Dickie and pretending to break off his relationship with Marge. Dickie walks in on Tom and is clearly disgusted and annoyed. He snaps at Tom that he is "not queer." Marge, though, believes that Tom is a homosexual. Tom denies this, but remembers the way that his circle of friends in New York (some of whom were openly homosexual) found his equivocation about his own sexuality annoying. Dickie, meanwhile, tells Tom that he has no romantic or sexual feelings toward Marge, but that he wants to preserve their friendship. Tom understands this, and they reconcile somewhat, giving Tom a feeling of hope. One day, an Italian man tells Tom that he can travel to Paris for free in a coffin as part of a drug-smuggling operation. Tom asks Dickie if he is interested. Dickie's response is contemptuous, so Tom takes Dickie to talk to the Italian man. When Dickie is clearly not open to the man's proposal, Tom loses his temper, feeling that his friend is acting arrogant and rude. Dickie, meanwhile, thinks that Tom's behavior is irrational and ridiculous. They have a public fight, during which Tom suddenly panics, realizing that he does not truly know Dickie and that it is not possible to truly know another person. Dickie buys him a few brandies, seeing that Tom is ill or otherwise unwell, but offers no comfort. Afterward, while Dickie is with Marge, Tom picks up the mail. He has received a letter from Mr. Greenleaf admitting defeat and telling him to return to America. The letter's content and businesslike tone only worsen his panicky mood. When Dickie returns home, Tom does not mention Mr. Greenleaf's letter. Instead he asks Dickie if he would like to go to Paris. Dickie says that they should go to San Remo instead, since it is nearer. Tom feels that this is a rejection, fitting into a pattern of Marge and Dickie trying to exclude him, but agrees to go to San Remo anyway.
On the train to San Remo, Tom is struck by the fact that he is annoying Dickie, and that any kindness on Dickie's part is mere politeness. Dickie tells Tom that he would prefer to take a planned winter ski trip with only Marge, and Tom pretends not to be upset. He then suggests going to Cannes, across the French border, before coming back to San Remo. In Cannes, Dickie and Tom spot a group of muscular male acrobats on the beach. Tom openly ogles them, and Dickie is disgusted, prompting Tom to shamefully remember Dickie's comments about his sexuality. Then, on the train back to San Remo, Tom is struck by the idea that he should kill Dickie and take on his identity. In doing so, he would be able to take all of Dickie's possessions and collect the regular checks that Dickie receives from a trust fund. He knows that such a pretense can't last forever, but is carried away by excitement and resolves to murder Dickie. In San Remo, he spots rental boats and asks Dickie to rent one with him. On the boat, Tom feels anxious and afraid, but knows that he cannot stop himself from killing Dickie. He uses an oar to hit Dickie repeatedly, staining the ship interior with blood. He then takes Dickie's rings and other possessions. He tries to dump Dickie's body into the water, but the body is heavy enough that he loses control of the boat, accidentally turning it on and causing it to spin uncontrollably. After nearly drowning, Tom manages to dump out Dickie's corpse, climb back into the boat, and sail it to a deserted-looking shoreline, where he fills it with rocks and sinks it.
In these chapters, Highsmith has a challenging task before her. She needs to find a way to build up to Tom's murder of Dickie, pushing him over the edge in a manner that is both surprising and seemingly inevitable. In order to do so, she has to bring us deep into Tom's mental state, giving readers an understanding of why someone might commit such a seemingly irrational act without making her protagonist appear so divorced from reality or normal emotion that he is no longer interesting. Therefore, in these chapters, Highsmith has to amplify the compulsiveness, lack of self-control, and self-aggrandizing behavior that Tom has displayed from the start, making his turn to violence part of a natural progression. In this analysis, we'll explore a few of the ways Highsmith manages this situation—both in terms of circumstantial changes that affect Tom's mindset and intensify his flaws, and in terms of portrayals of his mindset as he plans and executes Dickie's killing.
Tom Ripley, like most people, has trouble adjusting to sudden changes. He has more trouble than most, though, and is prone to severe mood swings when his circumstances change even slightly. Therefore, it makes sense that his crime would be preceded by a series of emotional highs and lows, which disrupt the fragile equilibrium he has and send him lurching from euphoria to despair. Therefore, starting at the beginning of chapter nine, Highsmith places Tom on a positive trajectory. He manages to gain Dickie's friendship and reap the benefits of Dickie's wealth, all the while receiving checks from Mr. Greenleaf. He isn't merely contentedly settling into a new friendship and life of comfort, though—he's feeling competitive and adrenaline-filled. For him, much of the pleasure he experiences comes from a sense of conquest over Dickie, which means that as long as Dickie seems interested in him rather than Marge, he feels wonderful. This isn't based merely on affection for Dickie—he's motivated by both unacknowledged but thinly veiled sexual desire and a longing for wealth and luxury. In the moment, Dickie's attention and Tom's access to his family money make him feel that he's "winning," especially against Marge. These pleasures are clearly temporary for a number of reasons, including his society's attitude towards homosexuality and Tom's own lack of family money. Yet Tom is so caught up in the rush of competition and pleasure-seeking that he doesn't acknowledge this temporariness, and he doesn't make an effort to hide his eagerness and competitiveness.
This lack of foresight makes his sudden downfall unexpected and devastating. Everything crashes down around him at once: Mr. Greenleaf withdraws his regular stipend, Marge and Dickie accuse him of being homosexual, and, in general, he begins to realize that his life in Mongibello will come to an end whether he likes it or not. Moreover, he's still so invested in his relationship with Dickie and his new lifestyle that he can't withdraw himself from the situation by traveling alone or giving Dickie some space. He therefore asks Dickie to continue traveling with him and remains visibly eager to engage with him, which only makes Dickie more annoyed and scornful and therefore makes Tom feel worse. He never deals well with disappointment—readers may conclude that he would have eventually committed a violent crime regardless—but this perfect storm is what finally drives him to the edge.
While this series of events accounts for Tom hitting a breaking point, it's also worth examining how Highsmith portrays his mindset during his actual murder and the planning that leads up to it. She foreshadows his decision to kill Dickie by showing the way Tom looks at his friend, noting how similar they look, and even dressing up as him. Ultimately, the decision to commit murder is driven equally by desire for Dickie and jealousy for him. Tom clearly has feelings for Dickie, and seems willing to kill him rather than deal with his rejection. However, his observations about their similarities, and his decision to assume Dickie's identity, reveal that he also envies Dickie's privileged lifestyle and easy attitude. By stealing his identity, he gains some of Dickie's wealth, but he also hopes to become like Dickie in a deeper sense, shedding himself in the process. As a matter of fact, he is driven by self-hatred as well. Tom runs away from his problems, and by taking on a new identity, he does so in the most dramatic way yet. His panicked tunnel vision while actually killing a person reveals that he does not so much revel in violence as turn to it desperately in moments of panic. Since he so often feels desperate and scared, though, his turns to violence are frequent and extreme.