South Korean director Bong Joon-ho is methodically (i.e. slowly) becoming a superstar of foreign cinema.

South Korean director Bong Joon-ho is methodically (i.e. slowly) becoming a superstar of foreign cinema.

Bong first grabbed American notoriety with 2006's monster movie satire "The Host," but it's his latest, "Mother" - only his fourth film in the past 10 years - that lifts him above the rest of the international pack. Its quiet simplicity allows the story to flow and the morally ambiguous characters to garner empathy, even when they probably shouldn't.

Kim Hye-ja, a beloved South Korean TV icon, plays the madcap title character (who is credited only as Mother), an herbalist and amateur healer who also acts as single parent to her son Do-joon (Won Bin).

A 27-year-old who shares a bed with his mother, Do-joon seems to have mental and emotional issues that occasionally cause outbursts, especially when someone calls him retarded.

Despite those shortcomings, their antics play more like uncomfortable dark comedy - but that completely changes when a neighborhood girl is found murdered on a rooftop and Do-joon is arrested for the crime.

Because Mother doesn't believe her son is guilty, she starts trying to track down the real killer by delving into the girl's secret world, unsure what she might find.

One of the film's biggest strengths is Bong's refusal to adhere to a typical storyline. The story continues to twist right up until the ultimate conclusion, a reversal of expectations that couldn't have come from anyone but a brilliant South Korean filmmaker.