During World War II, the United States military finds that its coded communications are being swiftly decoded by Japanese forces, compromising sensitive operations. To combat this, the U.S. employs the unique Navajo language as the basis for a new, unbreakable code. The film follows Marine Corporal Joe Enders, who is assigned to protect Navajo code talker Private Ben Yahzee—both of whom must overcome cultural differences and mutual distrust to operate effectively. Enders is scarred by previous battle experiences and wrestles with his demanding orders to protect the code above all else, including the life of his comrade, should their position be overrun.

As they plunge into the brutal chaos of the Battle of Saipan, the pair must depend on each other for survival. The plot delves into the complexities of friendship, honor, and duty, as Enders is torn between his mission to protect the code and his growing sense of duty to his fellow Marine. Their relationship is further complicated by Enders' battle-hardened exterior and the layers of guilt and redemption that he navigates throughout the film. Despite the horrors of war surrounding them, the two soldiers form an unlikely bond, fighting both the enemy and the challenges of their own internal conflicts.