As the evil Ugandan dictator Idi Amin, Forest Whitaker gives an unforgettable performance in The Last King of Scotland. Powerfully illustrating the terrible truth that absolute power corrupts absolutely, this fictionalized chronicle of Amin's rise and fall is based on the acclaimed novel by Giles Foden, in which Amin's despotic reign of terror is viewed through the eyes of Nicholas Garrigan (James McAvoy), a Scottish doctor who arrives in Uganda in the early 1970s to serve as Amin's personal physician. His outsider's perspective causes him to be initially impressed by Amin's calculated rise to power, but as the story progresses--and as Whitaker's award-worthy performance grows increasingly monstrous--The Last King of Scotland turns into a pointed examination of how independent Uganda (a British colony until 1962) became a breeding ground for Amin's genocidal tyranny. As Whitaker plays him, Amin is both seductive and horribly destructive--sometimes in the same breath--and McAvoy effectively conveys the tragic cost of his character's naiveté, which grows increasingly prone to exploitation. As directed by Kevin Macdonald (who made the riveting semi-documentary Into the Void), this potent cautionary tale my prompt some viewers to check out Barbet Schroeder's equally revealing documentary General Idi Amin Dada, an essential source for much of this film's authentic detail. --Jeff Shannon