Maternal devotion is taken to startling extremes in this rewarding Hitchcockian thriller from Korean director Bong Joon-ho (The Host). Beautifully shot and grippingly plotted, the film sees doting mother Kim Hye-ja prepared to go to any lengths to clear her adult son's name after the feeble-minded young man (Won Bin) is accused of murder. What follows is an eccentric and twisting whodunnit skilfully fused with an intimate and emotionally complex character study, as Kim's instinct-driven detective work reveals unsettling truths about both parent and child, as well as the small-town community around them. Echoing Bong's previous output, a seam of absurd and precisely paced humour adds unpredictability to the ostensibly simple story, defying genre conventions while playfully satirising the film's stereotypes. But it's the slow-burning marriage of suspense and melodrama that proves most effective, amplified by Kim's subtle performance, which elicits viewer sympathy no matter how deranged her determined heroine becomes.