While in Uganda on a medical mission, Scottish doctor Nicholas Garrigan (James McAvoy) becomes the personal physician and close confidante of dictator Idi Amin (Forest Whitaker). Although at first Dr. Garrigan feels flattered by his new position of power, he soon comes to realize that Amin's rule is soaked in blood, and that he is complicit in the atrocities. Garrigan faces the fight of his life as he tries to escape Amin's grasp.