Some of the most exciting and challenging films in the world these days are coming from Iran, so it's no surprise that A Separation, a tense and absorbing domestic drama packed with the suspense of a Hitchcock flick, recently earned the Academy Award for Best Foreign Language Film.

Opening Friday at AMC Quail Springs Mall 24, the movie unfolds like a Rube Goldberg machine powered by human fallibility, in which generally decent and sympathetic people with understandable motivations make choices that have unimaginably bad results.

At the center is an educated and reasonably well-off couple, Simin (Leila Hatami) and Nader (Peyman Moadi), seeking a divorce. Simin wants to move abroad with their child, but her husband refuses to leave the country because his aged father has Alzheimer's disease. Neither husband nor wife is willing to bend, and so begins a downward spiral.

Simin, who has been her father-in-law's caregiver, moves out of their apartment, forcing Nader to hire a devout Islamic woman named Razieh (Sareh Bayat) to tend for the old man while Nader is at work. But the job is considerably more than Razieh bargained for — the elderly man soils himself and wanders away from home — and the reluctant nurse decides on an unfortunate course of action that spurs another unfortunate choice, and so on.

Dire consequences mount, and to devastating effect. Writer/director Asghar Farhadi is a master at turning the screws, but he does so straightforwardly and always with an unflinching eye on revealing character. The filmmaker also has the benefit of a solid cast, particularly Moadi and Bayat as people trying to do the right thing within the constraints of their own convictions.

In A Separation, however, principles can be a disastrous thing.