Briefly, what is the film about?

The classic Alfred Hitchcock film Shadow of a Doubt chronicles the story of young Charlie and her suspicious Uncle Charlie. Charlie feels like her uncle is the only one who can understand her, and when she is ready for a little excitement, she decides to invite him to visit before discovering that he's already on his way. After Uncle Charlie arrives, though, a series of unusual happenings begins. Charlie discovers that Uncle Charlie is being chased by detectives who believe that he is the Merry Widow Murderer.