Eleanor is a 23-year-old US Navy nurse from Minneapolis, Minnesota, who enlists after experiencing unrequited love for her hometown pastor. Raised on a dairy farm, she possesses a strict moral code and a measure of innocence about the world. She finds herself stationed at the Cavite Naval Yard just as the war begins, subsequently becoming one of the first female prisoners of war in the Philippines.

Penny is a widowed US Army nurse from Houston, Texas, who joined the military to flee the grief of losing her husband and unborn child. She wears a gold nugget necklace that connects her to her family, who currently refuse to speak with her because of her enlistment. Stationed at Sternberg Hospital, she masks her emotional pain with a confident exterior and sharp humor.

Angelita, known as Lita, is a civilian Filipina nurse from a village on Leyte. As a mestiza mourning the recent death of her mother, she experiences guilt and feels like an imposter in her profession. Originally planning to immigrate to the United States to join her older sisters, she finds her priorities shifting as Manila falls under occupation.

Reyna is a highly skilled Filipina nurse and a former classmate of Angelita. She takes immense pride in her profession and is deeply patriotic, resenting nurses who view the job merely as a stepping stone to leave the country. Her brothers fight in the jungle as guerillas against the occupying forces.

Newt is a ten-year-old girl separated from her family at the beginning of the war. Left behind when her mother traveled and her father joined the guerillas, she survives as a pickpocket inside the prison camp. She attaches herself tightly to Penny Franklin, seeking safety and affection.

Akibo is a Japanese Army officer educated at Harvard. Serving as a translator and enforcement officer, he uses his perfect English and bureaucratic authority to torment the prisoners. He becomes fixated on Penny, continually offering her food and safety in exchange for becoming his mistress.

Charley is a captain in the Twelfth Regimental Quartermaster Corps. He uses bureaucratic paperwork as an excuse to spend time with Penny Franklin, eventually revealing his deeper feelings. He gives her his battle flag as a promise that he will survive the war.

Lon is a young corporal and medic stationed in the Philippines. Raised by a poor farmer, he dreams of moving to the United States to become a wealthy banker. He provides Angelita with emotional support and encourages her to take bold steps for her own survival.

David is an ensign in the US Navy whose path continually crosses with Eleanor Lindstrom's. At the Los Baños Prison Camp, he works tirelessly to keep morale up, sharing his meager rations and undertaking dangerous tasks to help the camp's starving children.

Kenji is a second-generation Japanese Canadian soldier. Drafted into the Japanese military after his family relocated, he hides his ability to speak English and his North American background from his superiors out of fear.

John is a pastor in Silver Lake. He serves as the primary reason Eleanor fled to the Navy, as his engagement to another woman broke her heart. He remains a constant fixture in her thoughts as she endures the horrors of the war.

Maude is the head Army nurse who guides her staff through evacuations, bombings, and eventual internment. She recognizes Penny's skills and actively shields the women under her command, serving as a surrogate mother figure when conditions become desperate.

Laura is the strict and disciplined supervisor of the Navy nurses. She volunteers her unit to travel deep into the jungle to care for prisoners at the Los Baños camp, believing it is their duty to face hardship rather than run from it.

Ida is a wealthy German civilian living in Manila. Because the Japanese classify her as an ally due to her nationality, she enjoys freedom of movement. She secretly uses her funds and access to smuggle critical supplies to the American prisoners and local orphans.

Father Domingo is a local Filipino priest who actively works with the Resistance against the occupying forces. He recruits civilian and military nurses to help smuggle messages, cash, and medical supplies into the heavily guarded internment camps.

Blanche is a fellow nurse and internee at Santo Tomas. She uses a regular deck of cards as a distraction to read fortunes, consistently drawing the eight of hearts when she reads for Penny.

Peg is a Navy nurse who endures the long imprisonment at Los Baños alongside Eleanor. She adopts a pragmatic, sometimes fatalistic view of their situation, frequently pointing out the futility of arguing with their captors.

Colonel Onozaki is a senior military officer who imposes strict new rules on the Santo Tomas prisoners. He aggressively limits food rations and cuts off the camp's access to external packages and mail.

Konishi is a cruel quartermaster and commandant at the Los Baños Prison Camp. He maliciously restricts the prisoners' access to food, forcing them to scavenge while leaving fresh deliveries to rot in the sun.

Dr. Nance is an American civilian doctor imprisoned at Los Baños. He insists on treating medical emergencies regardless of the patient's nationality, working under immense pressure to save lives within the camp.

General Wainwright is a senior military leader attempting to manage the failing defense of the Philippines. He coordinates the limited evacuation flights available, prioritizing the removal of women to save them from incoming atrocities.

Jim is an American civilian serving as a representative for the internees. He continually argues with the Japanese commandants over camp conditions, demanding they honor international agreements regarding the treatment of prisoners.

Sister Cecilia is a nun managing an orphanage at the Santa Catalina Convent. She protects children whose parents were killed in the conflict, relying on local nurses and smugglers to keep them alive.

Dr. Thomson is a strict physician working at the Little Baguio field hospital. He demands perfection from the nursing staff as they manage severe battlefield casualties under deteriorating conditions.