In 1955, one woman holds the key to America's future: a ruthless and beautiful ex-Nazi assassin, posing as a housekeeper inside President Eisenhower's isolated Gettysburg estate, waiting her chance to murder the chief executive and change the course of history. One man stands in her way: a disgraced Secret Service agent, driven from active duty by battle fatigue. Waiting and watching: the most powerful figures of the era, including Senator Joe McCarthy, FBI Chief J. Edgar Hoover, Vice President Richard Nixon, and the sinister pair of German-American brothers sponsoring the attack. As the minutes tick down, the highly-trained professional killer and the discredited WWII veteran face off in a deadly game. At stake: the life and legacy of Dwight D. Eisenhower, the world's most powerful man.