In 1963, the assassination of President Kennedy puts Vice President Lyndon Johnson in charge. But for all his grand ambitions and plans, his presidency will come to be defined by the slowly ticking time bomb of Vietnam. Thanks to a combination of arrogant and short-sighted advisors, a divisive political climate, and Johnson's own stubbornness, he commits to a gradual and irreversible series of decisions that leads to a bloody and unpopular war.