Nurse Ratched posts the patients’ financial statements on the bulletin board to show that everyone’s account, except McMurphy’s, shows a steady decline in funds. The other patients begin to question the motivations for his actions. When a phone call keeps McMurphy away from a Group Meeting, Ratched insinuates that everything he does is motivated by the desire for personal gain. Later, Harding argues that they have all gotten their money’s worth and that McMurphy never hid his con-man ways from them.

McMurphy asks Bromden if he can move the control panel, as a way of testing how big Bromden has grown. Bromden is able to move it half a foot. McMurphy makes a rigged bet with the other patients that someone could lift the control panel, knowing, of course, that Bromden has already lifted it. Bromden lifts it, and McMurphy wins the bet. Bromden, uncomfortable with McMurphy’s deceit, refuses to accept the five dollars that McMurphy offers him later. McMurphy asks why all of a sudden everyone acts like he is a traitor, and Bromden tells him it is because he is always winning things.

Ratched orders that everyone who went on the fishing trip be cleansed because of the company they kept. George has a phobia regarding cleanliness and begs the aides not to spray him with their smelly salve. McMurphy and Bromden get into a fistfight with the aides to defend George, so Ratched sends them to Disturbed. The kind Japanese nurse who tends them explains that army nurses have a habit of trying to run the place as if it were an army hospital and are “a little sick themselves.” One of the patients wakes Bromden during the night by yelling in his face, “I’m starting to spin, Indian! Look me, look me!” Bromden wonders how McMurphy can sleep, plagued as he must be by “a hundred faces like that,” desperate for his attention.

Nurse Ratched tells McMurphy that he can avoid electroshock therapy by admitting he was wrong. He refuses, telling her “those Chinese Commies could have learned a few things from you, lady.” He and Bromden are sent for the treatment, but McMurphy does not seem afraid at all. He voluntarily climbs onto the cross-shaped table and wonders aloud if he will get a “crown of thorns.” Bromden, however, is afraid and struggles mightily. During the treatment and afterward, Bromden experiences a rush of images and memories from his childhood. When he regains consciousness, he resists the fog and works to clear his head, the first time he has managed to do so after receiving shock therapy. He knows that this time he “had them beat,” and he is not subjected to any more treatments. McMurphy, however, receives three more treatments that week. He maintains an unconcerned attitude about it, but Bromden can tell that the treatments are affecting him. Ratched realizes that McMurphy is growing bigger in the eyes of the other men because he is out of sight, so she decides to bring him back from Disturbed.

The other patients know that Ratched will continue to harass McMurphy, so they urge him to escape. McMurphy reminds them that Billy’s date with Candy is later that night. That night, McMurphy persuades Turkle to open the window for Candy. She arrives with Sandy in tow, carrying copious amounts of alcohol. Everyone mixes vodka with cough syrup, while Turkle and McMurphy smoke joints. Sefelt has a seizure while with Sandy, and Harding sprinkles pills over them both, declaring that they are “witnessing the end, the absolute, irrevocable, fantastic end.” Sometime after four in the morning, Billy and Candy retreat to the Seclusion Room.

As it gets closer to morning, they realize that they are going to have to figure something out before the staff arrives. Harding tells McMurphy that they can tie up Turkle, so it looks like the mess created by their party was all part of McMurphy’s escape attempt. Turkle can keep his job, the other patients will not get into trouble, and McMurphy can drive off to Canada or Mexico with Candy and Sandy. McMurphy asks whether any of the rest of them would want to escape with him. Harding replies by saying that he is almost ready to leave on his own, with all “the traditional red tape.” He says that the rest of them are “still sick men in lots of ways. But at least there’s that: they are sick men now. No more rabbits, Mack.”

McMurphy and Sandy climb into bed after asking Turkle to wake them up right before the morning staff arrives. Unfortunately, Turkle falls asleep, and the aides discover them in the morning. Bromden surmises that the ensuing repercussions were inevitable, whether or not they followed through with McMurphy’s escape. He figures that even if McMurphy had escaped, he would have had to come back and not let the nurse get “the last play.”

The next morning all the patients are incredulous about the night’s activities. As Ratched turns up more and more incriminating remnants from the party, the patients cannot keep their laughter in, and the nurse looks like she is going to “blow up like a bladder.” McMurphy has a chance to escape when Turkle undoes the screen to let Sandy out, but he refuses, despite Harding’s warnings of what is to come. When Ratched finds Billy with Candy, he is calm and peaceful. He and Candy both move “like cats full of warm milk.” The nurse threatens to tell Billy’s mother. Billy regains his stutter and begins to cry, begging her to keep it a secret and blaming Candy, McMurphy, and Harding for the whole thing. She sends him to Spivey’s office to wait while she clears things up with the other patients. But Billy ends up committing suicide by cutting his throat.

Nurse Ratched asks McMurphy if he is satisfied with his accomplishments, and then she retreats to the Nurses’ Station. Bromden realizes that nobody will be able to stop McMurphy from rebelling, because it is the need of the patients that has been encouraging him all along, “making him wink and grin and laugh and go on with his act long after his humor had been parched dry between two electrodes.” Then, McMurphy smashes through the glass door, rips open the front of Ratched’s uniform, and tries to strangle her. As he is pried off of the nurse, he gives out a cry “of cornered-animal fear and hate and surrender and defiance.”

Several of the Acutes transfer to other wards, and some check themselves out of the hospital altogether. The doctor is asked to resign but refuses. Ratched returns after a week on medical leave with a heavy bandage around her throat, unable to speak. She cannot regain her former power over the ward. Eventually the only patients left on the ward are Bromden, Martini, and Scanlon. McMurphy is given a lobotomy for his attack on Nurse Ratched. When he is returned to the ward after the operation, he is a vegetable. That same night, Bromden suffocates McMurphy with a pillow. He throws the control panel through a window screen and escapes from the hospital, hitching a ride with a trucker.

Ratched makes one last feeble attempt to regain control when she uses the same principle she used earlier to ensure the patients’ submission to her authority: divide and conquer. She begins to sow the seeds of distrust among the patients by publicizing the financial gain McMurphy has enjoyed since his transfer from the work farm. Harding defends McMurphy, pointing out that McMurphy has more than repaid the patients’ financial losses by providing them with the means to resist Ratched’s influence.

But it is McMurphy’s timing of the rigged bet on the control panel that proves extremely disadvantageous. He fleeces them of their money too soon after Ratched has planted the seeds of doubt in their minds. Bromden is affected most acutely, because he feels that McMurphy has used him to take advantage of the others. Only after McMurphy regains the patients’ trust by taking on yet another personal risk for their benefit—defending George against the aides—do Bromden and the others realize McMurphy’s true objectives. Even Bromden helps this time, demonstrating the extent to which he has regained his self-confidence.

McMurphy’s self-sacrifice for the benefit of the other patients begins to surface after he defends George, and also when he undergoes the electroshock treatments. McMurphy is belted to a cross-shaped table, an obvious allusion to a crucifix. This Christ imagery suggests an impending martyrdom on the part of McMurphy, and he even compares himself to Christ when he asks whether he gets to wear a crown of thorns. Of course, a martyr ultimately must sacrifice himself to save others. This proves true, since although Bromden feels strong enough to withstand the effects of the electroshock, McMurphy weakens under the repeated treatments. Bromden finally begins to feel that his victory over the hospital is complete. He is no longer ruled by his fears or his past, thanks to the help of his unlikely savior, McMurphy.

After Nurse Ratched provokes Billy, leading to his suicide, McMurphy truly does become a Christ figure for the patients. Under the invisible but heavy pressure of the other patients’ expectations, McMurphy makes the ultimate sacrifice to ensure that Ratched cannot use Billy’s death to undo everything they have gained. By attacking Ratched and ripping her uniform, he permanently breaks her power but also forfeits his own life. Though Ratched tries to give McMurphy a fate worse than death by having him lobotomized, Bromden dignifies McMurphy by killing him, assuring that McMurphy will always be a symbol of resistance instead of a lingering cautionary tale for future patients on Ratched’s ward.