Doctor Pearson (Michael Rennie), who works at a Canada hospital in the province of Quebec, receives a series of Poison pen letter. More letters, all signed with the mysterious picture of a feather, are delivered to others in the small Canadian town. Cora Laurent (Constance Smith), the wife of the main doctor - Dr. Laurent (Charles Boyer) - at the hospital, receives a letter accusing her of having an affair with Pearson. Another letter informs a shell-shocked veteran Mr. Gauthier that he is dying of cancer, causing the distraught man to commit suicide. Quickly, the townsfolk begin pointing fingers at all possible suspects.