Frustrated that Marines are being wounded during house entries, Kyle trades his sniper rifle for a Marine’s M-16 and leads room-clearing operations. Using his specialized SEAL training, he takes command of assault tactics and trains Marines in room-clearing techniques. The team encounters various threats. In one house, Kyle kills a group of fighters who turn out to be Chechens. In another basement, they find two tortured Iraqis; one is dead and the other dies during treatment. To accelerate their work, Kyle directs an armored vehicle to ram through walls and shoot doors. They clear 50-100 houses daily; Kyle loses over 20 pounds in body weight.

As combat intensity decreases in his sector, Kyle returns to sniper overwatch overlooking a large cemetery. A major firefight erupts there; Kyle kills multiple targets. A communications specialist calls in a close air strike that kills over 30 insurgents. When an Iraqi sniper in a mosque minaret pins down Marines, an air strike decapitates the sniper before the bomb explodes in an alley, killing more insurgents.

When SEAL command recalls their snipers, other SEALs warn Kyle he could face discipline for fighting on the ground. An East Coast SEAL lends Kyle his M-4. Kyle is reassigned to Lima Company and continues leading assaults. While assisting another unit, he tries to rescue a mortally-wounded young Marine who asks him not to tell his mother he died in pain. The Marine dies in Kyle’s arms.

Kyle recalls his Thanksgiving meal that year—turkey and sides mixed in a single box, eaten with their hands. After a week at Lima, Kyle returns to Kilo Company, assigned to hold a cordon along the Euphrates with his .300 Win Mag. Insurgents use a marsh across the river for cover, attacking nightly. A nearby Coalition Iraqi Army camp repeatedly fires at their position despite friendly markers. Runaway rejoins Kyle’s position but again flees during a firefight; he is later transferred. The SEALs attempt to burn the marsh vegetation using white phosphorus, thermite grenades, and homemade explosives, but the wet conditions thwart their efforts. Requests for heavier ordnance are denied by higher command. Kyle shoots four inflatables being used by 16 Tunisian insurgents to cross the river, causing them to drown or be killed by Marines. He makes his longest confirmed kill at approximately 1,600 yards, hitting an insurgent who thought he was safe. Kyle notes that he aimed for his targets’ center mass, not their heads.

After a week, Kyle is sent back to Baghdad. En route, his vehicle is hit by an explosive device, but he and another Fallujah veteran remain unfazed. Kyle’s platoon arrives from the Philippines, initially jealous of his combat experience. He rejoins them for less dangerous direct-action missions.

Kyle is assigned to a personal security detail (PSD) in the Green Zone, working in advance cover for the Iraqi Vice President’s convoy, which he detests. After Kyle nearly has Marines fire on unidentified vehicles that belong to the vice president’s unannounced friends, he is fired from the PSD job and attached to an Arkansas National Guard unit providing sniper overwatch on Baghdad’s Haifa Street during Iraqi elections. He shoots kidnappers attacking a young man.

Taya recounts how, one night, Kyle calls her from an overwatch position. A firefight erupts; an RPG hits nearby. He drops the phone without ending the call, and Taya hears the battle before the battery dies, terrifying her.

One day, a sniper called Smurf claims Kyle’s chosen spot; Kyle relocates and still gets a kill. A vehicle transporting the team is hit by a massive explosive, temporarily deafening Kyle, but the vehicle continues. Kyle’s platoon moves to Habbaniyah alongside the Army’s 506th Regiment. Morale drops as they do construction work instead of combat operations.

Taya recalls Chris being misdiagnosed with terminal tuberculosis and his fatalistic acceptance of death in combat.

Kyle’s platoon resumes direct-action raids. During an overwatch for an Army convoy, Kyle shoots an armed man approaching the convoy’s route. An inexperienced Army unit investigates, initially believing the man’s wife that he was unarmed and carrying a Qur’an. Kyle is put on stand-down for three days while a colonel investigates. The investigation clears Kyle, but his platoon refuses to provide further overwatch support for that unit. Kyle expresses his frustration with the Rules of Engagement.

Kyle finishes the deployment with a substantial number of confirmed kills, approaching Carlos Hathcock’s legendary Vietnam-era total of 93.

Taya describes her excitement waiting on the tarmac for Kyle’s return, contrasting herself with another SEAL wife’s jaded attitude.

After seven months away, Kyle bonds with his son, who is now crawling and a more expressive personality then when a newborn. The transition home is difficult; Kyle remains in a combat mindset and isolates himself for a week. He and Taya argue over parenting decisions, such as their son co-sleeping with her. Neighbors who have helped Taya during his deployment throw a welcome-home barbecue for Kyle. Kyle displays immature behavior at home, including trimming bushes with a lawnmower and exposing his buttocks to a neighbor. He admits his temper has become explosive, leading to road rage incidents.

Taya describes the emotional distance between them after his return. She is shy about sexual intimacy, feeling they must get to know each other again.

During his time home, Kyle attends a specialized school in New Orleans where FBI, CIA, and NSA officers teach skills like lock picking and car theft. To prove their undercover abilities, they are tasked to infiltrate a strip club with surveillance devices. Kyle steals a car off Bourbon Street for his final exam, returning it later. He attends parachute recertification at Fort Benning, describing his fear of heights and the dangers of jumping. In one incident, he is stolen by another jumper’s canopy and falls 70 feet, breaking several ribs. Kyle enjoys flying on the benches of open helicopters, calling it a tremendous adrenaline rush despite his fear of heights.

On July 4, 2005, while watching fireworks, Kyle is overcome with sadness about his friend, Marcus Luttrell, reported missing in Afghanistan a few days earlier. The news shatters Kyle’s sense of invincibility. Days later, he learns Luttrell has been found alive but is severely injured. Kyle becomes a Subject Matter Expert (SME), briefing senior officers on sniper tactics, a role he despises because commanders often ignore his advice or have already made decisions.

Taya describes their arguments over his decision to reenlist. She believes his priority should be family over country but cannot force him to make that decision.

Kyle’s platoon receives new members, including men called Dauber, Tommy, and Ryan Job. Kyle and others initially target Job for not looking like a typical SEAL, but his determination, hard work, and humor eventually win them over. Another new SEAL, Marc Lee, joins the platoon. Lee is athletic and deeply religious, quickly fitting in. On a training mission, Marc admits he has never been “choked out.” i.e., losing consciousness while in a chokehold. Kyle and others proceed to do this repeatedly on Marc. Kyle praises his new commanding officer and Command Master Chief Primo, an aggressive Texan who protects Kyle and another Texan SEAL named Pepper when they get into trouble.

Kyle gets two tattoos—a Trident and a crusader cross in red—which causes friction with Taya. She becomes pregnant with their second child. As deployment nears, they grow more emotionally distant from each other. Kyle explains his desire to return to war, citing his love for the job and belief that his country needs him. Days before deploying, Kyle has a seizure while having a neck cyst removed. A corpsman helps conceal the incident from his medical record to prevent medical discharge.

Taya’s late-pregnancy checkup shows complications with the baby, including the umbilical cord around her neck, breech position, and low amniotic fluid. Doctors schedule an emergency C-section. Taya bleeds significantly during the surgery, and Kyle fears for his wife’s life, making him reconsider Taya’s experience of his high risk-to-life on deployment. Their daughter is born healthy; he holds her and feels an immediate bond. When he offers the baby to Taya, she initially refuses in exhaustion, causing Kyle to panic internally, but she soon reaches out and takes her. Two days later, Kyle deploys again.