Bill Farrell and Marge Bradley are excitedly preparing for their wedding when Bill begins to exhibit strange and detached behavior. Concerned, Marge tries to understand the sudden change in her husband's personality. What she does not realize is that Bill has been replaced by an alien impostor who is part of a larger invasion plan. These aliens come from a dying planet and have been systematically replacing humans in the small town. The behavior patterns and growing number of emotional disconnects among people raise suspicions but are initially dismissed or misunderstood, leading to increased anxiety for Marge.

As Marge's unease grows, she gradually uncovers more disturbing evidence that confirms her fears. Certain townspeople, particularly men, act inexplicably strange, adding weight to her suspicions about Bill. Seeking answers, she confides in friends and eventually allies with another skeptical local. Together, they uncover secrets that point to a nefarious extraterrestrial agenda. While organizing for a confrontation and attempting to alert the authorities about the impending danger, they face resistance and disbelief from a community already compromised by the silent invasion.