Unforgettable story of a child murderer in Berlin. Police are helpless to stop him so the German underworld unite to catch him. Impressive, ahead of it's time melodrama that perfectly captures the frailities of the legal system, mob hysteria and a killer's psyche all in one finely woven tale. Peter Lorre is fantastic as the tortured, doomed killer. You'll think of this movie every time you hear "Hall of the Mountain King", which is what Lorre whistles before an attack. M is director Fritz (Metropolis) Lang's masterpiece. It features impressive Impressionistic sets that add mood and atmosphere to the tension. In German with subtitles. Remade in 1951.