Nicholas Garrigan (McAvoy) has just finished medical school and decides to go out into the world in search of adventure. He randomly picks Uganda, arriving on the heels of a political coup; the new leader takes a shine to the young man and appoints him the presidential physician. Nicholas is a fictional character. Unfortunately, the man who becomes his boss—General Idi Amin—is not, and the self-declared African king would earn a spot in the dictator hall of fame after killing more than 300,000 of his countrymen.
As played by Forest Whitaker, Amin is all belly laughs and bear hugs, until something, anything, triggers a mood swing. Then the monster beneath the jovial surface emerges, and all hell breaks loose. After finally scoring another character as meaty to dig into as Charlie Parker, the actor attacks the part with fangs and talons; he actually seems to be channeling the late Amin whenever he goes into one of many sweaty, eye-rolling rants.
The rest of the film, alas, never reaches such heights. Having cut his teeth on documentaries, Kevin Macdonald acts as if a shaky-cam aesthetic alone is enough to fuel dramatic tension. Once the story’s Candide thoroughly loses his innocence, the film switches into a series of flat romantic interludes and chase scenes set to a stock score (generic Afropop for joyous occasions, flaccid acid rock for suspense). Whitaker keeps Last King propped up as long as he can, but even the burly thespian can’t sustain such a crumbling foundation. (Now playing; Click here for venues.) — David Fear