From observing Sister Loretta’s behavior in recent catechism classes, Ben and Mary Anne deduce that a sex education lecture is imminent. The day before the scheduled class, Ben overhears Father Pinckney refusing Sister Loretta’s request that he teach the boys, admitting he gets too embarrassed, believing that the students already know more than he does.

Sister Loretta separates the boys and girls. A nurse from the naval hospital speaks to the girls while Sister Loretta addresses the boys. She begins by explaining that nuns and priests experience sexual urges but have suppressed them to serve Christ, earning a higher place in heaven, and that sex is beautiful only within marriage for procreation, not for pleasure.

When two boys giggle, she orders them to hold hands as punishment. She then warns the class about masturbation, describing it as disgusting to God, who summons the Blessed Virgin, angels, and saints to express their hatred of the act while Satan celebrates with demons. Ben remembers that when he first experienced ejaculation, he thought he was bleeding to death. Over the years, nuns and priests have warned him that masturbation causes fatigue, warts, pimples, and madness, with one nun suggesting plucking out offending body parts to avoid hell. Sister Loretta concludes by recommending prayer to the Virgin Mary, keeping religious statues facing the bed, and placing rosary beads on nightstands.

On Christmas Eve, the Meecham family prepares for midnight Mass. Mary Anne and the children tease Bull about the Christmas tree he purchased. The family walks to church singing carols, and Lillian spontaneously breaks into a dance down the street; the whole family joins in until they near the church, where Bull orders them to stop.

During Mass, Ben serves as an altar boy. He reflects on believing in God more fully on Christmas Eve, preferring the Christ Child to the suffering adult Christ. He notices Sister Loretta praying intensely in the front row and Bull standing at the back, where he always is. Ben is ambushed by vivid sexual fantasies about Ansley Matthews and struggles to concentrate on his altar boy duties, but when the priest elevates the host during consecration, Ben sets aside his fantasies.

Returning home, Lillian warns Ben that Christmas will be lean due to expenses and college costs ahead. Ben reminds her that she says that every year, and it is never true. As is tradition, that night, Bull climbs onto the roof to impersonate Santa Claus. At five in the morning, Mary Anne wakes Ben, and they find an enormous pile of presents under the tree—once again revealing that Bull and Lillian have spent lavishly despite her warnings.

The children wrestle Bull out of bed in their traditional Christmas morning ritual. Bull makes them chant his supremacy as the Great Santini before permitting them downstairs, then he slowly drinks coffee to build their anticipation before distributing presents.

The day after Christmas, Sammy Wertzberger picks up Ben, excited about a surprise: He has arranged a double date in Charleston with two college freshmen. He has introduced himself to one of them as Rock Troy, claiming to be a basketball star, and he asks Ben to back up the persona. As they drive to Charleston, Sammy discusses his invented approaches to seduction and plans to impress the girls with stories of imaginary trips to Europe with Ernest Hemingway. He smokes cigars he claims are imported from Barcelona.

When they arrive, a man in a dark suit informs them that one girl’s fiancé arrived unexpectedly from Yale, and when the other tried to reach Rock Troy in Ravenel, no one had heard of him. Sammy and Ben return to the car and dissolve into uncontrollable laughter that continues as they visit several Charleston bars on the drive home.

On a Friday afternoon, Lieutenant Colonel Cecil Causey, commanding officer of a rival squadron and another good friend of Bull’s, calls Bull to propose a joint happy hour between their squadrons. Causey was badly burned in Korea when he flew a burning plane away from a populated area before ejecting; plastic surgeons rebuilt his face, but it remains motionless on one side. He asks Bull to have one of his pilots teach a lesson to one of his pilots, Lieutenant Beasley, notorious for losing three planes in four years and known for wearing an ascot, Bowie knife, and cartridge belt. Bull summons Captain Brannon, a powerfully built officer with a violent temperament, tells him Beasley has been insulting him, and orders him to handle it if anything starts at happy hour.

At the Officers’ Club that night, Bull is called to the phone—in a prank, Mary Anne has called pretending to be Lillian, triggering the traditional penalty of buying everyone drinks when one’s wife calls. Bull realizes that she orchestrated the prank and threatens her.

Following a prearranged plan, Cecil pours beer over Bull’s head, Bull punches Cecil, and both squadrons brawl. Brannon attacks Beasley. The fight ends in under two minutes when military police sirens approach. When MPs arrive, the pilots are calmly drinking at the bar; Beasley has been carried out injured, and a captain sits with the commanders wearing Beasley’s distinctive costume as a decoy.

Before the biggest basketball game of the year, against Peninsula, Bull arrives home early. He orders Ben to nap and obsesses over the college scouts who will be there. Despite Lillian’s request, he has been drinking. At the pregame meal, he dictates Ben’s menu of toast and tea. In the locker room, Bull barges in to tell Ben that four college scouts are present and he should score 40 points; the players can smell bourbon on his breath, and Ben hustles him out.

During the game, Ben plays brilliantly and develops mutual respect with the other team’s center, Wyatt Sanders. Ben scores 21 points in the first half, though Peninsula leads by six. After Peninsula guard Peanut Abbott forearms Ben in the head following a missed layup, Bull rushes from the stands screaming at Ben to retaliate or not come home. Ben is awarded foul shots but misses both. Bull paces the sideline, following Ben and shouting orders.

Ben deliberately feeds the ball to Abbott, follows him downcourt, and undercuts him on a layup. Abbott falls hard, breaking his arm. A brawl erupts, and Ben is ejected from the game. As he leaves, Bull congratulates him and praises his killer instinct. In the locker room, Ben weeps with shame. Principal Dacus arrives and tells Ben the bone broke through the skin; he bans Ben from all varsity sports for the remainder of his time at Calhoun High, calling the action cowardly and unforgivable. That night, Lillian enters Ben’s room and silently holds his hand.

On Saturday, Sammy picks up Ben in his father’s Cadillac. He has a shotgun and announces his plan to scare lovers parked at the beach by firing near their cars. Ben reluctantly agrees. They approach a vehicle parked under trees on a secluded dirt road and discover that it belongs to Deputy Sheriff Junior Palmer. Despite Ben’s protests, Sammy sneaks close enough to identify Palmer’s companion and returns breathless: Palmer is with a Black woman, and Sammy muses that Palmer’s reputation in town would be ruined if this were revealed.

They sprint back to the Cadillac and speed away. Sammy, ecstatic, immediately proposes blackmailing Palmer for $50. He drafts a letter demanding Palmer leave the money on the catwalk of the St. Catherine’s Island water tower. Ben initially resists but agrees to go along as Sammy’s partner, insisting that the scheme is entirely Sammy’s idea. They joke about splitting the proceeds, which Sammy claims he will donate to keeping himself drunk until graduation.