Louie Zamperini's story begins in 1929 when he is 12. Louie is the son of Italian immigrants living in Torrance, California. From toddlerhood, Louie is a daring, out-of-control child. On the way to kindergarten, he takes up smoking cigarette butts that he finds on the way. He starts drinking alcohol at the age of 8.
Numerous stories are related about Louie's miscreant behavior, the total opposite of his older brother, Pete. But Louie is also described as big-hearted and tough, resilient and not easily discouraged. He is confident of his abilities and cleverness, and never gives up. When he reaches high school, Pete convinces Louie to join the track team, and eventually Louie's energy and time funnel into track. He finds he excels at it as he breaks records in every meet. Louie becomes a track superstar and qualifies for the 1936 Berlin Olympics. Louie learns there that he is too undisciplined and inexperienced to win a medal in Berlin. He returns to Torrance and begins to train for the 1940 Olympics in Tokyo.
Life for Louie doesn't proceed according to plan. Because of illness, he loses his speed and many races, and his chance for the Olympics evaporates. He leaves college a few credits short of a degree and takes a welding job at Lockheed. Louie then joins the Army, training as a bombardier as the United States is bombed at Pearl Harbor and enters World War II.
At an air base in Washington, Louie meets his 26-year-old pilot, Allen Phillips (nicknamed Phil), along with the rest of the bomber crew who are assigned to a B-24 nicknamed Superman. They are sent to a base in Hawaii, and the crew flies its first bombing mission over Wake Island. (The pilots of the raid each earned the Distinguished Flying Cross.) Considerable detail is given regarding the dangers facing airmen. Surviving a crash in the ocean was nearly impossible. More than the fear of being eaten by sharks was the fear of being captured by the Japanese, who typically tortured, then executed, their prisoners of war. Louie and Phil return to their main base in Hawaii, minus four of their crew — lost to injury and death in the bombing raid.
When yet another B-24 goes missing, Phil, Louie and their remaining crew are ordered to search for the missing plane. Since their own plane is no longer air-worthy, they are forced to use a problematic B-24 called Green Hornet. True to form, Green Hornet has engine failure, and the aircraft crashes into the ocean.
Louie thinks no one will survive, and he almost doesn't. Though tangled in a web of electrical wires in the plane, which is sinking fast toward the ocean floor, Louie gets free and surfaces. He sees Phil, who has a bad head injury, and the tail gunner, Mac. Louie manages to grab two life rafts and tie them together before rescuing Phil and Mac. Louie bandages Phil's head as best he can and slips him into the second raft. Each raft measures only 2 feet by 6 feet.
Drifting west, the men are thirsty and hungry and roasted by the sun. Their upper lips swell so much that their nostrils are obstructed. They barely survive by eating albatross and fish, and collecting water from infrequent rain. After six days pass with no fresh water, the men bow their heads and pray to God. Louie promises God that he will dedicate his life to Him if his thirst is quenched. The water runs out twice more, at later times, too, but they pray together each time, and the rain comes each time. After 40 days on the raft, Louie hears voices singing and sees 21 human figures in the sky. He is sure it is real, that he is not hallucinating.
On the 27th day, an aircraft appears, and Louie fires two flares. The plane flies away, and then returns, but it turns out to be a Japanese bomber. It repeatedly strafes the rafts. Surprisingly, it misses the men but damages the rafts so that one becomes useless and the other is halfway submerged, which leads to shark attacks. Eventually Louie is able to patch most of the holes while Phil and Mac work at inflating the raft and fighting off sharks with an oar. Louie discovers that the second raft serves as a decent canopy to block the sun. The men continue to fight off sharks, and they even figure a way to catch the smaller ones and eat the liver.
Mac's decline continues, and on the 33rd night, he dies. Louie slides Mac's body into the ocean. On the 40th day, Phil and Louie see land and decide to wait until nightfall to go ashore. They know they are in enemy territory. Before they reach land, however, a typhoon strikes and tosses them around. They tie themselves to the raft and survive.
The next morning as they attempt to row to shore, a Japanese boat spots them. The soldiers capture Phil and Louie, tying them to a mast and threatening them with a bayonet. The captain has the crew untie them and gives them a biscuit and water before transferring them to another boat. From there, they are blindfolded and led onshore to an infirmary.
Each man finds as he is weighed that he has lost about half of his body weight, and later as they are interrogated, they learn they have drifted 2,000 miles and are in the Marshall Islands. The Japanese take good care of them for two days in the infirmary before transferring them to another atoll, Kwajalein, a location Louie recognizes as Execution Island. The officer says they cannot guarantee their lives after that. Arriving at Execution Island, Phil and Louie are thrown into separate, squalid cells. Conditions are so bad that Louie yearns for the raft.
In his cell, he hears the same voices from the sky singing, and they give him hope. He prays fervently, hour after hour. Japanese officers continue to interrogate Phil and Louie, trying to get them to divulge military secrets. Their guards are abusive and do their best to humiliate and degrade them.
One day they get a new guard named Kawamura, who identifies himself as a Christian. He befriends them and shows them kindness. After 42 days, Louie and Phil are transferred to Yokohama, a place even worse than Kwajalein. This one is called Ofuna, secret from the rest of the world, where international laws don't apply. The Japanese do whatever they want. Beatings occur for the smallest infraction of the many detailed rules. Conditions deteriorate, and the captives live with the realization that the Japanese will kill them all if the United States invades. After a year and 15 days in Ofuna, Louie and a few others are transferred to another POW camp called Omori.
At Omori, Louie meets Mutsuhiro Watanabe, nicknamed the Bird. The Bird is the disciplinary officer for the camp, and he makes Louie the object of his wrath. Best described as deranged, the Bird beats Louie nearly every day. At one point, the Japanese try to use Louie as a propaganda piece, but he refuses, and they let him know that he will be transferred to another camp. Before that happens, the Bird is transferred to a camp far away from Omori, and life improves for the men. Then Louie is transferred to a remote camp called Naoetsu. When he arrives there, he keels over in the snow when he sees that the Bird is commander there, and he is once again the target of beatings.
As WWII enters its final stages, the POWs learn that the Japanese plan to execute all POWs on Aug. 22, 1945. Even following the atomic bombings of Hiroshima and Nagasaki, things don't change at the camp. Louie continues to pray ceaselessly for deliverance from his circumstances, fighting nightmares about the Bird beating him to death. One week away from the termination date, the men suddenly notice all the guards have disappeared, and they find the guards gathered around a small radio listening to what looks like an important announcement. Later, one of the Japanese officers announces that the war is over. The men struggle to believe it is true. The fact is confirmed a short time later by a U.S. torpedo bomber flying past them, signaling with its code light that the war is over, and that it will return the next day with provisions; yet it is a week before anything is dropped.
Louie eventually returns home a hero, but he is plagued by anxiety and nightmares and slowly succumbs to alcoholism. He meets Cynthia, a wealthy, beautiful young woman in Miami Beach, and knowing little about each other, they marry in a short time. Louie's problems — financial as well as emotional — continue to beat him down. Mentally, he can't leave behind his POW experiences, and he is obsessed with wanting to murder the Bird. His anger and violence escalate to an out-of-control level that eventually threatens his wife and child. Cynthia leaves him, with their daughter, intending to divorce him.
After Cynthia attends a Billy Graham crusade, she convinces Louie to go with her to another. Louie recalls his prayers and promises from his time on the raft. He responds to an altar call and leaves the crusade a changed man. In the ensuing year, Louie becomes a Christian speaker, telling his story across the country.