The cinematic odyssey embarks with Jane, who is ensnared in a web of haunting nightmares, waking in a haze of confusion. Meanwhile, her partner Mac shares a seemingly innocuous cup of coffee with their neighbor Bill. Bill, attempting to lighten the atmosphere with a flirtatious remark, only deepens Mac’s growing unease about the strange behavior enveloping them. Seeking solace, Mac comforts Jane, and together they dismiss their burgeoning apprehensions as mere paranoia.
Transitioning to a local high school, we find 17-year-old Kim grappling with feelings of isolation from her peers. Back at the hospital, Jane meets an unwelcome advance from her supervisor Ethan, leaving her feeling distressed. In their neighborhood, Mac is accosted by Sara, a jogger who attempts to flirt with him, much to Kim's surprise as she witnesses the encounter before Sara darts away. The unsettling atmosphere escalates when an air-raid siren blares, prompting them to seek refuge inside Mac and Jane's home.
As they huddle together, they catch an emergency radio broadcast urging everyone to head to public schools or shelters, a stark deviation from earlier advice to stay put. Upon returning home from her hospital shift, Jane reveals Ethan's troubling behavior has progressed to aggressive advances. Bill appears once again, this time returning a power saw and offering hollow reassurances that everything will be fine, only to impose himself into their home, igniting a fierce confrontation with Mac.
The aftermath sees Jane gripping a shotgun while Bill lies confined in their basement, helpless. During the ensuing interrogation, Bill espouses his warped beliefs — that to embrace the unknown is to attain joy by relinquishing negativity. Although the group resolves to keep Bill restrained, their plans are interrupted by the arrival of Kurt, Kim's uncle. Mac struggles to relay the day's bizarre events, only to be met with skepticism, complicating matters further when Kurt uncovers Bill’s predicament, leading to intense discussions about the ethics of their actions.
Stepping outside, Kurt is met with a throng of curious onlookers, and the memory of Sara’s kiss leaves him feeling vulnerable. Meanwhile, in the dimness of the basement, Jane, caught off guard by Bill's own aggressive behavior, suffers an unexpected gunshot wound. The shock of alien energy courses through her, awakening a profound understanding that she shares with Mac, urging him to recognize the significance of her transformation, with promises that the rewards far surpass any initial fear.
The tension mounts when Kim and Mac receive a puzzling text message compelling them to switch on the television. Kathy Walters, the news anchor, maintains a soothing tone contrary to the mayhem surrounding them, assuring viewers that acceptance of this extraordinary change is the key to their salvation. The revelation strikes: those afflicted are not just humans but an alien species.
Confronted with an uncertain fate, Mac and Kim decide to take a stand, brandishing weapons against the encroaching chaos at their doorstep. Their fates now dangle precariously in the balance as they plunge into the uncertainty that lies ahead.
