The incredible tale of Louis Zamperini originally came to the screen in 2014 in Angelina Jolie's Unbroken. The film chronicled the Olympic athlete's long survival at sea on a raft after his bomber was shot down in World War II, and showed how he stayed alive, spirit intact, through the brutality of Japanese POW camps.

"The first film covered my dad’s life until the end of the war," says son Luke Zamperini of Louis, who died in 2014 at age 97. "But that was far from the end of his incredible journey."

A spiritual second chapter, Unbroken: Path to Redemption, just wrapped filming for release in 2018 and revealed its first images exclusively to USA TODAY.

The faith film delves into Zamperini's personal struggles after his hero's return to America, his embrace of Christianity and his ultimate act of absolution — traveling back to Japan to forgive the war camp guards who made his life a living hell.

Producer Matt Baer says he and Jolie wrestled with how to include this portion of Zamperini's life in the first film. Ultimately, it was too massive to fully dramatize and was instead alluded to at the end.

"It boiled down to doing justice to this section of Louis' life. That's just not possible in one two-hour film," Baer says.

Harold Cronk (God's Not Dead) stepped in for Jolie to direct the follow-up, also based on Laura Hillenbrand's best-selling book Unbroken.

Path to Redemption follows Louis (played by Chicago P.D.'s Samuel Hunt) to post-war Florida, where he starts to rebuild after meeting Cynthia (Merritt Patterson), who will become his wife. Zamperini grapples with what would today be diagnosed as post-traumatic stress disorder (PTSD).

He dreams of cruel beatings from notorious camp commander Mutsuhiro Watanabe, known as "The Bird."

"Louis had this thirst for revenge," Baer says. "If he was able to get back to Japan, find Watanabe and kill him, (he thought) that would end his nightmares. His life became harder and harder. Psychiatric care for World War II veterans was non-existent then."

Spiraling into alcohol abuse, Zamperini flails through life and marriage until he chances upon evangelist Billy Graham's revival tent in 1949. Graham is played by his grandson, pastor William Graham. "I don't know if I'm the best actor," Graham says. "But I am a preacher."

The pivotal meeting starts a faith journey for Zamperini and a lifelong friendship with Graham.

"Hearing Billy Graham's sermon, my father was reminded about promises made to God on the life raft and in the prison camp: that he would seek out and serve God should He get him home alive," Luke Zamperini says. "When he got off his knees after saying the Sinner's Prayer, he was done getting drunk and done fighting. And he had forgiven his prison guards."

A year later, Zamperini makes the trip to Japan to forgive the guards face to face (although Watanabe refuses to meet him).

"With all that Louis endured physically in war — being lost at sea for 47 days, prison camps for two years — this movie highlights his most remarkable achievement," Baer says. "That he was able to eventually forgive his captors."