Shay, a psychiatrist who specializes in post-traumatic stress disorder (PTSD), juxtaposes the narrated memories of his patients who are Vietnam veterans to the story of Achilles in Homer's Iliad. He finds that the roots of their illness, like that of the ancient hero, lie in betrayal of duty by senior officers who failed to do "what's right," in the repression of grief, and in the social limitations imposed on expressions of love between men.

These stressors lead to guilt, wrongful substitution, and dangerous rage, called the "berserk" state. The mental pathology is fostered by an equally wrongful failure to honor the enemy; return to "normal" is never possible. The book concludes medically with recommendations for prevention.