During an African medical mission in the 1970s, Scottish doctor Nicholas Garrigan (James McAvoy) impresses brutal Ugandan dictator Idi Amin (Forest Whitaker, in an Oscar- and Golden Globe-winning role) by acting swiftly in a crisis and becomes the dictator's personal physician. Garrigan enjoys the perks of his new position, until he begins to become aware of Amin's inhumanity -- and his own complicity.