被解雇的报社女记者安·米歇尔伪造了一封信给报社,署名“约翰·杜伊”(即无名氏),信上表示对这个充满恶瘤的社会充满失望,决心要自杀。报社为此不得不重新聘用了安来调查此事。然而,没想到此事最终引发了一场政治运动……As a parting shot, fired reporter Ann Mitchell prints a fake letter from unemployed "John Doe," who threatens suicide in protest of social ills. The paper is forced to rehire Ann and hires John Willoughby to impersonate "Doe." Ann and her bosses cynically milk the story for all it's worth, until the made-up "John Doe" philosophy starts a whole political movement. At last everyone, even Ann, takes her creation seriously...but publisher D.B. Norton has a secret plan.