I NOTICED HER LEGS FIRST. They were cut off and sewn back on where her arms should've been. As the camera panned down a metal hospital gurney, it was obvious her upper extremities suffered the same fate—hacked off and sewn onto her lower torso. Welcome to Uganda.

The Last King of Scotland tells the story of Ugandan dictator Idi Amin (played with charisma—and a lazy eye—by Forest Whitaker). It starts happily enough: The Ugandan people are all for Amin's 1971 overthrow of Prime Minister Milton Obote. They dance in the streets, sing, and clap. It's nice. Things are good. Then, of course, things get heavy.

A big bruiser with a bigger ego, Amin's paranoia overtakes him, and the man that dubbed himself "His Excellency President for Life Field Marshal Al Hadji Dr. Idi Amin, VC, DSO, MC, King of Scotland, Lord of All the Beasts of the Earth and Fishes of the Sea and Conqueror of the British Empire in Africa in General and Uganda in Particular" turns barbarous.

This is no spoiler if you know your history, but by the end of Amin's rule in 1979, some 300,000 of his own people had been butchered in the name of purity and progress.

The true story is told by introducing a fictional character, a young Scottish doctor who becomes ensnared in Amin's crusade. It's a controversial move, injecting fiction into history—but it allows for a greater sense of intimacy with Amin, as Dr. Nicholas Garrigan (James McAvoy) soon becomes the man's most trusted advisor. Again, then things get heavy.

While beautifully shot and flawlessly acted, Last King is intensely savage. You might be appalled and you might be disturbed. Get over it. Like Hotel Rwanda or Schindler's List, this is important history, and the kind of thing that, if it went down today, would play second fiddle to news stories about cats stuck in trees and Oprah's weight. This could happen anywhere—and it has, too many times. Know your history—before you're killed, dismembered, and sewn back together by our own damn government.