In The Last King of Scotland, everyone but Nicholas Garrigan--the young Scottish doctor who heads to Uganda in 1970 to work in a village clinic but stumbles into the inner circle of newly installed president Idi Amin--seems to be aware of cinema's hoary African trope: Whitey can check in any time he likes, but he can never leave. A brittle Gillian Anderson, playing a doctor's wife, knows it; the newcomer's breezy take on philanthro-tourism hardens her almost before our eyes. Even the injured cow Garrigan shoots with Amin's gun, in the act that catalyzes their relationship, seems to be bleating out in warning.

And yet director Kevin MacDonald (Touching the Void) makes it difficult not to become a co-conspirator in Garrigan's boundless naiveté. The film, an adaptation of Giles Foden's 1998 novel, was shot entirely on location in Uganda, and MacDonald revels in painting a picture of rapturous, brochure-friendly Africa and its people in bloom; lushly saturated colors and a joyous soundtrack bring us closer to Garrigan--played by the unforgivably hot James McAvoy--and his similarly unforgivable blinkers.

Garrigan's daddy issues are set up quickly and in a rather facile way, as many of the key themes will be; when he locks hands with the famously charismatic Amin, played, in a remarkably ferocious turn, by Forest Whitaker, the stage is set for what will develop into an intensely complicated, abusively oedipal bond. Whitaker gives the role of the maybe-despot a magnetic underpinning--from his initial Shecky Amin showmanship and shameless one-liners to his wounded rage after a later assassination attempt--that inclines us to wave down all of his character's red flags. Amin, put in office by the British government and perhaps that country's most ill-conceived protégé since Guy Fawkes, offers Garrigan a job as his personal physician, which quickly escalates into that of his "closest advisor." Garrigan cheerfully accepts all the perks of being clutched to a dictator's bosom, and for most of the film you can hardly blame him; MacDonald's Uganda is a veritable bootie-poppin' bacchanal, packed to the rafters with hot pants and high '70s kitsch. Sure, Garrigan gets sent on some questionable errands and Amin's fuse gets shorter and shorter, but everyone thinks their boss is a nutjob, right?

When Garrigan begins an affair with one of Amin's wives (played by Kerry Washington), however, things get serious. Dead serious. Forgive me for that, but the turn the film takes in the last 20 minutes, when everyone pays for their sins at the hands of the suddenly clearly insane Amin, is almost too jarring to be believed. "I am the father of this nation," Amin tells Garrigan, before stringing him up by his nipples, "and you have offended your father." Whitaker's riveting performance as the unraveling Amin is where this film wants to be; instead we're stuck with Garrigan's Jesus Christ pose, and the expected out that amounts to little more than, "Forget it, Nick. It's Africa."