M (1931)

Fritz Lang's chilling 1931 masterwork, *M*, plunges audiences into a grim Berlin gripped by terror. In this classic German thriller, Hans Beckert, a serial killer who preys on children, becomes the focus of a massive police manhunt. Beckert's heinous crimes are so repellant and disruptive to city life that he even becomes targeted by others in the seedy underworld network, who fear police scrutiny will ruin their own illicit operations. With both cops and criminals in pursuit, the desperate murderer soon realizes that people are on his trail, sending him into a tense, panicked attempt to escape justice. Though not a traditional "whodunit," *M* is undeniably one of the "Best Mystery movies" for its groundbreaking approach to the police procedural and criminal investigation, fundamentally shaping the genre for decades to come. As one of the earliest and most effective sound films, Lang masterfully uses sound (like Beckert's signature whistle) to build suspense and reveal character. The film brilliantly weaves two parallel investigations – the methodical, modern police force and the ruthless, efficient underworld – into a taut narrative. Its exploration of mob rule, the psychological torment of a killer (portrayed unforgettably by Peter Lorre), and the very nature of justice makes it a profound and terrifying cinematic achievement, establishing the template for the manhunt thriller and pushing the boundaries of what a crime mystery could be.