In 2011 I interviewed a Lieutenant-Colonel in American Military Intelligence. What he told me confirmed what my research had already uncovered: that American intelligence knew a great deal more about Kennedy's assassin, Lee Harvey Oswald, before November 22, 1963, than they have ever publicly admited. This is the story of how lost opportunities, and a massive intelligence failure, resulted in one of the greatest tragedies in American history--the assassination of John F. Kennedy.