John F. Kennedy is celebrated as one of America’s greatest presidents, but his legacy hides a dark truth. If he had lived to serve a second term, he would have triggered a nuclear war, wiping out much of the world’s population. Nineteen years after the disaster, a group of scientists in an underground bunker develop a method to send a person’s consciousness back in time. Their only hope for survival is agent Wayne Bronson, who must inhabit the body of Lee Harvey Oswald in 1963. His mission: assassinate Kennedy and stop the apocalypse before it begins.