Time Out says
One of Hitchcock's finest films of the '40s, with Cotten as the infamous 'Merry Widow' murderer, who takes refuge with the small-town family of his sister (Collinge). Focusing on adoring niece Wright's dawning realisation that her kind, generous and handsome uncle is in fact a cold and cynical killer, the film is not only psychologically intriguing (both niece and uncle are called Charlie, and he arrives in town as if in answer to her prayers for excitement), but a sharp dissection of middle American life, in its own quiet way an ancestor of Blue Velvet. Is Uncle Charlie all these gentle folk deserve, when adolescent girls dream of the romantic life, and middle-aged men (papa Travers and neighbour Cronyn) endlessly discuss gruesome murder? Funny, gripping, and expertly shot by Joe Valentine, it's a small but memorable gem.
Cast and crew