A young American soldier is sent to fight in the Vietnam War and returns home safely but has PTSD. He has constant nightmares, seeing death and the ghost of a Vietnamese soldier he killed. He feels guilty because he lived, and his buddies didn't. He believes a Monarch butterfly saved his life because she led his rescuers to him as he was dying. He believes God will never forgive him for killing people. As time passes although peculiar, he falls in love with a Monarch butterfly named Mari Posa. He believes he has gone insane but doesn't care, especially when he starts conversing with Mari whom he tries to save. When she dies, he takes her to her homeland in Mexico. There the unbelievable happens that only the spirit world understands.