A man wakes from a car crash suffering with amnesia. After the accident, he flags down a passing car, but the driver dies in the crash as it swerves off the road. He checks his wallet and discovers the name Liam Hartwell. With no memory of who he is or where he belongs, Liam trudges toward a nearby town and stops at a roadside diner, only to find the entire place abandoned and everyone inside dead. Believing the air to be contaminated, he uses a torn piece of his shirt to cover his nose and mouth and presses on.
Following a map from the diner and the address on his driver’s license, Liam locates his house. Inside, news reports hint at biological warfare, and he begins sealing the windows with tape. Peering outside, he spots a farmer and rushes to warn him to leave the area, but the farmer collapses and dies. Liam notices that animals nearby also die, and he realizes he is the cause of the unexplained deaths, not a virus.
A woman also suffering with amnesia arrives at Liam’s home, revealing that she was with him during the crash. The woman, [Jane Doe], has a calmness around Liam that permits her to approach him without dying, which frightens Liam because neither of them knows why they were traveling together or what caused the crash. The two of them investigate the crash site and discover a charred circle. Liam shares his theory about the deaths, while Jane reacts with fear and asks Liam to keep his distance. A passing police officer encounters them and dies when Jane walks away.
To prove his point, Liam uses a goat to demonstrate that living beings near him die unless Jane stays within a certain distance—within about 15 meters. Jane, who was CT scanned after the crash, agrees they should be tested, so they drive to a hospital. By now, Liam knows he is linked to the deaths and is wanted by the police. Officers arrive as a doctor informs Liam that he is healthy. Fearing separation, Liam and Jane flee. Jane briefly recalls a missing-person poster, and when she refocuses, Liam has already entered an elevator without her. He urges the occupants to leave as soon as the doors open, while he tries to isolate himself until Jane can rejoin him. They eventually leave the hospital together, relieved that no one else has died.
A news report finally reveals Rose Daerwood as Jane’s true name. Her husband, Sam, pleads for her to come home. Rose convinces Liam that they should seek Sam’s help, but Sam is slow to believe their story. Liam once again demonstrates the pattern of animal deaths when they get too close to him. Sam explains that Rose disappeared while searching for her missing twin sister, Lily. Rose recalls being suicidal and that Liam saved her life. As Liam and Rose grow closer, Sam becomes jealous. The couple plans to flee to Liam’s remote cabin, but Sam calls the police and then regrets it, warning them too late. A chaotic pursuit follows—police officers and bystanders die as Liam and Rose are separated, forcing Sam to concede to the plan.
On the way to the cabin, Liam and Rose learn that an unexplained cosmic anomaly struck Earth at the spot of their accident. While exploring the cabin, Rose uncovers evidence that Liam is a serial killer who abducted and killed her sister Lily. Separately, Liam remembers attempting to abduct and kill Rose at the time of the cosmic anomaly. Confronting Liam, Rose is taken hostage along with Liam by a man and his two adult sons. The father orders his sons to kill Liam. Rose allows them to separate her from Liam, and the remaining son shoots Rose. Liam’s aura kills the remaining son, and Liam drives Rose to the hospital. There, as Rose is taken away for treatment, Liam shoots himself in the head.
