On the very first day of the invasion of Sicily, three months into his combat career, Allan Knepper flew his P-38 Lightning fighter in a squadron sent out to sweep the island and interdict German ground targets. Retreating German infantry unexpectedly pounded the American flyers. Knepper was one of two shot down; he was never found. Knepper’s story is the story-in-microcosm of thousands of American fighter pilots in World War II.