It's 1957 and lawyer James B. Donovan is recruited from his prestigious law firm to defend accused Soviet spy Rudolf Abel - an unenviable task. Donovan hasn't practiced criminal law since he was a prosecutor at the Nuremburg trials after World War II.  Also, the strong anti-Communist mood at the time makes him a target from who think Abel should just be executed. Abel is convicted but Donovan convinces the judge to sentence him to prison, as at some point in the future it may be possible to swap him for an American spy the Soviets have in custody.  Just such a scenario comes into play when in 1960 U-2 spy pilot Francis Gary Powers is shot down over Soviet territory and taken prisoner.  Donovan is again recruited to travel to East Berlin and act as intermediary and negotiate swapping Able for the American.