Don is on comfortable ground again with because he has a new project: the Don Project. 

Don begins by getting help and instruction from Claudia. They meet a coffee shop, where Don orders coffee in a more sociable manner, rather than his more efficient (and therefore curt) way. Claudia compliments him on the subtle changes, surprised that his visit to the notoriously brusque New York has improved his social skills. However, she knows the bulk of the change can be attributed to the effect Rosie has had on him. To get an even better grasp on behavior considered acceptable, Don role-plays social scenarios with Claudia so he can practice responses. While he learns quickly, Claudia worries that changing himself too much for Rosie will lead to resentments. 

To further his emotional education, Don watches romantic movies, including some of Rosie’s favorites. In the process, he realizes that fidelity is fundamental to all successful romantic relationships. As he immediately think of Gene and Claudia, he shares this information with Gene. He says that if Gene loves Claudia, he should be willing to make sacrifices to make her happy—namely, put his research aside and be faithful. Rather than confront his behavior, Gene says, “I’ll think about it when I see you changing the habits of a lifetime” (252).

After tackling his social skills, Don addresses his rigid schedule by abandoning his standardized meals and shopping for different types of food. This is not as difficult as he had feared; in fact, he finds himself enjoying it. Don wants to share his new discoveries with Rosie. However, he is not unrealistic; he knows he will have to work hard to improve his social skills and that he may not be successful in convincing Rosie to be in a relationship with him.

As he contemplates the potential loss of his job, Don decides to deal with his complaint against Kevin. He calls the student into his office and asks why he didn’t write the paper himself. After further questioning, which proves Kevin does understand the subject matter, Kevin explains he is not confident writing in English. Worried that his limited literacy might jeopardize his success, he had his tutor rewrite his paper without thinking it through. With his own recent experiences as a rule-breaker in mind, Don decides to give Kevin an additional assignment instead of expelling him. For the first time, Don puts himself in the dean’s shoes and realizes how difficult her job really is. 

Finally, Don addresses his appearance. He realizes that the real motivation behind how he dresses is that he enjoyed people thinking he was unconcerned with societal norms. Claudia helps him shop for a new wardrobe, and Don follows that up by getting new glasses and a haircut—he models himself after Gregory Peck because, back in New York, Rosie told him they shared a resemblance.

Now that the Don Project is complete, he embarks on the Rosie Project. Dressed in the style of Gregory Peck, Don goes to Rosie’s office and asks her to dinner that night. Next, he goes to Gene’s office, where he hands Gene an envelope containing an unspecified invitation and then confronts him about his unacceptable behavior. Gene tells Don that he’s one to talk, since everyone thinks Don is completely oblivious, but that is exactly Don’s point. Despite Gene’s opinion of himself, everyone else thinks he is sleazy. Don tells Gene it’s time for him to grow up and put his wife and family first; otherwise, he might lose them.

Don changes into a jacket and pants in his office and schedules an appointment with Phil Jarman, Rosie’s father. Before Don has a chance to leave, the dean comes in and leads him to her office. Don believes he is going to be fired, and it suddenly triggers a memory where, mirroring the “flounder demonstration” (262), an 11-year-old Don was reprimanded for disrupting his religious studies class with too many questions. Don and the dean reach her office, where she asks whether he has an explanation for his behavior. But before he can answer, Dr. Lefebvre breezes in, carrying Don’s fake proposal, and announces that he is pledging $4 million to Don’s project. He still believes that Don’s unconventional proposal was the dean’s idea, and he tells her to Don must be on the project team, effectively saving Don’s job. Don, with his new social skills, recognizes what is going on and leaves the office to avoid embarrassing the dean by telling the truth.

Phil, a visibly intimidating man, is a physical trainer who owns his own business. He recognizes Don immediately, presumably from the photo of Don and Rosie from the faculty ball, and demands they go through with the physical assessment that was the pretext for Don’s visit. He get Don a pair of boxing gloves, then insists that Don really should try to hit him while they spar. 

Don attempts to carry out a conversation during the assessment, telling Phil that Rosie is upset with him for several reasons—of note, that he did not follow through on his promise to take her to Disneyland. He calls Rosie Phil’s stepdaughter, which shocks and angers Phil. Don throws a punch that breaks Phil’s nose and knocks him down. Phil explains that he made the Disneyland promise only once: at Rosie’s mom’s funeral. By the time he got out of rehab for his injuries from the crash, eight months later, he thought Rosie had forgotten all about the promise. Phil asserts that he tried to do his best for Rosie, but Don refuses to let Phil get up, saying, “Not until we solve the problem” (266).

With that settled, Don prepares for dinner by changing his outfit, putting an unspecified envelope into his jacket pocket, and a ring box in his pants pocket. He thinks to himself that, even if the night doesn’t go the way he hopes, he is happy with the way he has changed.