In San Francisco, Captain Theodore Breakstone, the district legal officer of Com Twelve, wonders how to handle the Caine Mutiny. The case was a disaster and the investigation has made it worse. No legal officer will have a part in defending mutineers. Lieutenant Commander Jack Challee, who is to prosecute the case for the Navy, comes to Breakstone and exclaims that he has found a suitable defense: Barney Greenwald, a hotshot Jewish Lawyer from New York who joined the military as a fighter pilot when the war broke out. Breakstone finds Greenwald less than eager to take the case. Greenwald is convinced that he can get his clients off, but does not want the mutineers to walk free.
When Greenwald meets Maryk, he changes his opinion the case. Greenwald had expected a wimpy, self-satisfied businessman, but finds a dejected, blunt ex- fisherman. When Greenwald meets Keefer, he realizes that Keefer is to blame for the mutiny, for he is the complainer. Greenwald reveals that more than forty ships made it through the typhoon without floundering or changing course, which shakes Maryk. He and Greenwald begin to formulate a plan for the defense. Greenwald asks about the Caine's action after the mutiny. Queeg was detained for psychological review, but because of a desperate shortage of sweepers, the Caine continued on to Lingayeng Gulf. Queeg had not protested at Maryk's continued command of the ship, and Maryk performed admirably, sustaining a kamikaze strike and successfully piloting the ship back to port. Greenwald says they will plea not guilty to the charge of prejudice of good order and discipline (reduced from mutiny by Breakstone).
Willie flies home to end his relationship with May. He has decided to stop stringing her along. Willie thinks about how far he has come in his naval career, beginning as a scared ensign and becoming someone the crew looked up to as a battle-seasoned war hero. Willie was surprised to find that the investigation preceding the court martial was not grand, but made him feel like an insignificant, small part of an insignificant, small procedure. Willie is scared by the possibility of being convicted, and for the first time since his Princeton days thinks, "Mother will get me out of it."
Mrs. Keith meets Willie in the airport. She is surprised by Willie's thin body and jagged face. The drive home to the Manhasset house is silent, and Willie finds the house feels strangely unfamiliar. Willie tells his mother of his plan to dump May. After getting permission to see her that night, Willie calls May's old number, but finds she has moved to the Hotel Woodley. May and Willie go to a coffee shop. May tells Willie she is supporting the family through her singing career. She is also going to school at night and helping out in the store. She tries to impress Willie with the French and book-talk that she has picked up in school. Willie is shocked by the poverty of her apartment, and worried, for May is sick.
That night, Willie goes to see May sing at the Grotto Club, formerly the Tahiti club. May sings well and looks beautiful. Later, the couple kiss, but May breaks it off. After a few more bitter kisses, they break up. May knows exactly why Willie is breaking up with her, and tells him so. He cannot answer her accusations. Willie has progressed, but he is partly still a stuck-up Princeton boy.
On the first day of the court martial, Captain Queeg is examined by the judge advocate lieutenant Challee. Maryk almost falters in the opening minutes of the proceedings after hearing the solemn reading of the charges and the swearing-in of the military jury. Queeg also shakes Maryk. Spending time away from duty and in the sun in his Arizona home has completely erased the paranoid Queeg of the typhoon and replaced him with a dignified, well-spoken officer. Queeg answers the questions with clarity and sanity. He testifies that in the storm, Maryk's pride in his seamanship had doomed them. The rest of the examination establishes Queeg's experience, his perfect naval record, and his perfect sanity. In his cross-examination, Greenwald forces Queeg to recognize the two excellent fitness reports he gave Maryk, which contradict Queeg's statement that he had suspected Maryk from the start.
Keefer testifies and is a huge disappointment to the defense, denying any evidence of insanity in Queeg and even speaking against Maryk. Greenwald chooses not to cross-examine Keefer. Challee calls Paynter and Harding to help excuse Queeg's decision to deny the officers sleep. Urban also testifies, denying that the captain acted crazily. In his cross examination, Greenwald asks Stilwell to explain the towline cutting incident, but Challee objects, and the entire series of questions is stricken from the records. Other members of the crew testify that they had never found Queeg's actions to be crazy. However, on cross examination, Greenwald establishes that none of these crew members are qualified to determine whether Queeg was crazy. Greenwald drinks heavily that night, and Maryk believes his case is hopeless.
Willie does well for Maryk in his testimony. He maintains that the captain had lost control of the ship. Willie bluntly says that the captain was terrified, and gave orders only after Maryk suggested them. Willie is forced to admit that he was antagonistic to Queeg at times. In the crucial moment of his testimony, Willie is asked whether he sided with Maryk out of concern for Queeg's mental state or out of personal dislike of Queeg. Willie cannot bring himself to lie in court for Maryk's sake and says he cannot remember how he felt. In his cross- examination, Greenwald asks Willie why he disliked Queeg, and Willie talks about Queeg's cowardice. All of Challee's objections are overruled, as cowardice in a command is a grave flaw in the Navy. Willie mentions how Queeg smuggled alcohol aboard and then extorted money from Willie to pay for its loss. Captain Randolph Southhard testifies as an expert witness on ship handling and says that Queeg's actions were prudent. Greenwald makes Southard look silly by making him admit that he calls himself an expert despite never experiencing typhoon conditions or sailing on a minesweeper destroyer. Greenwald forces Southard to admit that in extreme circumstances Maryk's decision may have been prudent.
At first, Willie's decision to break up with May seems like a positive sign of his growing maturity. It seems noble of him to decide to stop leading her along and wasting her time. However, Wouk makes it plain to us that Willie loves May, but chooses to take the easy way out and break up with her. Willie is not willing to choose happiness over the money and comfort that comes with making his mother happy. Willie is making the mistake his father warned him against in the last letter he wrote to Willie.
Lieutenant Greenwald is introduced as an eccentric, brilliant, somewhat cocky man. It is Greenwald who introduces the idea that the mutineers were not as righteous as we think they are. We saw events from Willie's point of view, and under the stress of the typhoon, he felt the decision to mutiny was clear. During the court martial, however, other ways of viewing the mutiny begin to filter through. We begin to see the possibility that the crew acted out of spite more than anything else. There were other options in the situation beyond outright removal of Queeg from command. Wouk makes us feel exactly what Willie feels, and in this way we see how it is possible to think one thing in the heat of battle, and something else entirely in the clarity of peacetime. Evidence mounts against the mutiny, including Queeg's appearance in court, the easiness and clarity of his speech, the testimony of the crew who were otherwise not seen in the novel, and the psychological report.
Tom Keefer's testimony finally exposes him as the coward he is. Though he was the one who turned the officers against Queeg and got Maryk to question Queeg's sanity, he lies in court in order to save his career. He even speaks against Maryk. Greenwald immediately understands Keefer's guilt, but does not bring it out in court, knowing that it will be easier to get Maryk acquitted by presenting him as a lone hero, rather than as a member of a disgruntled gang of officers.