Dorrigo is a surgeon and Australian soldier who becomes a leader of a thousand prisoners of war in a Japanese camp along the Burma Railway. Haunted by feelings of inadequacy and an overarching sense of emptiness, he relies on poetry and the memory of a woman he met in a bookstore to sustain his spirit. Though he acts heroically toward his men, earning their deep respect and the moniker "Big Fella", he views himself as a fraud and a man destined for isolation.

Amy is a restless, vibrant young woman married to Dorrigo's older uncle. She feels trapped in a comfortable yet passionless life and desires adventure over predictability. Her fierce attraction to Dorrigo provides him with a rare sense of meaning, though her own motivations and desires often confuse her.

Nakamura is the pragmatic and conflicted Japanese commander of the prisoner of war camp. Addicted to a drug called shabu, he suffers from delusions but remains firmly committed to the progress of the railway and the glory of the Emperor. He justifies his extreme cruelty as an honorable sacrifice made for his nation's progress.

Choi Sang-min is a formidable Korean guard at the camp, frequently known to the prisoners by an animalistic nickname due to his brutal methods. Operating under the demands of the Japanese army, he uses violence to assert power over the starving men. He harbors deep resentment and believes that inflicting pain gives him a fleeting sense of freedom in a life otherwise devoid of autonomy.

Darky is an unusually optimistic and resourceful Australian prisoner who consistently tries to find a bright spot in dire situations. He steals food to help his weaker comrades and maintains a spirit of camaraderie during starvation and sickness. His unwavering positivity makes him a prime target for the guards' cruelty.

Ella is a woman from a prominent Melbourne family who marries Dorrigo. She represents safety and social expectation to him, though he finds their relationship dull. She remains devoted to her husband despite his emotional distance and frequent absences, seeking to build a stable family life.

Keith is Dorrigo's older uncle and a pub owner. He is a generous, practical man who provides his young wife with financial stability but lacks the passionate spark she craves. He frequently hosts Dorrigo and maintains a quiet, fatalistic view of his own crumbling marriage.

Jimmy is an Australian prisoner who serves as the camp's bugler. He faithfully plays the "Last Post" at the funerals, honoring the dead even as his own body deteriorates and swells from illness. His bugle serves as a rare symbol of dignity and remembrance in the squalor of the jungle.

Kota is a chilling and zealous Japanese officer who views the railway project as a sacred battlefield. He reads Japanese poetry but executes extreme, dispassionate violence, viewing his prisoners merely as instruments for the Empire's progress.

Rooster is a bitter and hateful Australian prisoner who clings to discipline and prejudice to survive. He memorizes passages of text to exercise his mind and harbors an intense dislike for Darky Gardiner's unfailing optimism.

Tiny is an enormous Australian prisoner whose initial physical resilience makes him a target for the guards' punishing quotas. As his health eventually fails from disease and exhaustion, he receives essential care from his fellow prisoners.

Jack is an Australian prisoner suffering from severe ulcers and gangrene. He undergoes multiple harrowing amputations in the camp hospital in a desperate bid for survival.

Tom is Dorrigo's older brother and a veteran of World War I. He returned from his own war deeply traumatized, communicating his grief through silence, and serves as Dorrigo's earliest model of a broken man.

Guy is an Australian prisoner who obsessively sketches the realities of the camp. He documents the atrocities and the daily lives of the men so that their suffering might be remembered by the outside world.

Bonox is a medical orderly in the prisoner camp who assists Dorrigo in the cholera and ulcer tents, striving to save the men despite the horrific conditions and lack of supplies.

Mrs. Rainbow is Jack's wife back in Australia. She speaks with Dorrigo after the war, sharing her pragmatic, profound views on the fleeting nature of love and companionship.

Sato is a Japanese doctor who befriends Nakamura after the war. He shares his philosophy on discovering patterns in the world and bonds with Nakamura over their shared wartime complicity.

Ikuko is a kind and supportive woman who meets and marries Nakamura after the war. She helps him secure employment and cares for him during his illness, bringing out what he perceives as his better qualities.

Jessica is one of Dorrigo and Ella's three children. She grows up in a household marked by her father's frequent absences and emotional distance.

Mary is one of Dorrigo and Ella's three children. She relies on her parents to guide her safely through a sudden environmental disaster.

Stewart is the son of Dorrigo and Ella. Like his sisters, he navigates childhood under the shadow of his father's complex emotional unavailability.

Jodie is the daughter of Jimmy Bigelow. Her inquiries prompt her aging father to reflect on the scattered memories of his youth and his time in the camp.