Yasuko, who had been living bravely while running a lunchbox shop, is confronted one day by her ex-husband, Togashi. In a moment of life-threatening danger from the violent gangster Togashi, Yasuko and her middle school daughter, Misato, commit an impulsive act of murder. Just then, Ishigami, a high school math teacher who lives next door, steps in and offers to help the desperate mother and daughter. As detectives struggle to make sense of Togashi’s murder, they seek the help of brilliant physicist Yukawa. Yukawa soon realizes that Ishigami had crafted a seemingly simple and obvious trick—one that manipulated assumptions and distorted perspectives.
What underpinned both the perfectly logical murder scenario and the small cracks that ultimately shattered it was, in the end, the fragility of human emotion. How far can empathy and devotion to others truly go? Even though there is no single correct answer to happiness, another form of blind faith—put through an ‘imperfect proof and theorem’—leads only to tragic ruin. Adapted seamlessly to the screen from Higashino Keigo’s celebrated novel, often considered his masterpiece, this film draws strength from its intricate setup and emotional depth. (KIM Yong-eon)