Amy Boyle Johnston, author of the 2015 book “Unknown Serling,” found the story while looking through Serling’s papers at the University of Wisconsin. Serling, who died in 1975, had yet to start a family when he wrote “First Squad, First Platoon.” But he was already thinking about the next generation, including a dedication to his yet-unborn children urging them to remember “a semblance of the feeling of a torn limb, a burnt patch of flesh” and “the hopeless emptiness of fatigue” were as much part of war as “uniforms and flags, honor and patriotism.