Hitchcock thriller. Young 'Charlie' Newton (Teresa Wright) longs for something exciting to happen to brighten her dull existence in Santa Rosa with parents Joseph (Henry Travers) and Emma (Patricia Collinge). The arrival of her Uncle Charlie (Joseph Cotten) seems to be just what she needs: urbane, witty and charming, the elder Charlie has announced that he wishes to quit New York to spend some time with his family. Uncle Charlie soon makes himself at home, but his suspicious behaviour begins to unsettle his niece. When police detective Macdonald Carey (Jack Graham) tells Charlie that he believes her uncle to be none other than the Merry Widow murderer, she begins to question whether she really knows Uncle Charlie at all.