This film tells: During World War II, USMC corporal Joseph F. "Joe" Enders returns to active duty with the aid of his pharmacist, Rita, having previously survived a gruesome battle on the Northern Marianas Islands against the Imperial Japanese Army that killed his entire squad and left him almost deaf in his left ear. Enders' new assignment is to protect Navajo code talker Pvt. Ben Yahzee, and carries a promotion for Enders to Sergeant in a Joint Assault Signal Company. Sgt. Pete "Ox" Henderson also receives a parallel assignment protecting Navajo code talker Pvt. Charlie Whitehorse.
Yahzee and Whitehorse, childhood friends from the Navajo tribe, are trained to send and receive coded messages that direct artillery fire. Enders and Henderson are instructed to kill their code talkers if capture is imminent so that the code cannot fall into enemy hands. As Enders and Henderson meet Yahzee and Whitehorse, it becomes apparent that the two experienced Marines are less than happy to be babysitting their Navajo codetalkers, and the Navajos must also endure racial harassment by some of the white Marines, notably Private Chick. During their missions, however, Henderson and Whitehorse discover a mutual love of music. Enders and Yahzee also discover that they have much in common, notably their Catholic upbringings.