Viral 2016

Two high-school sisters, Stacey and Emma, have recently moved to a quiet suburban area in California where their father will take on a new role teaching high school science. Emma finds it challenging to fit into the community, while Stacey quickly makes friends and even lands a boyfriend, CJ. The family dynamics are tense, with Emma’s mother away and the parents’ relationship strained, a tension that becomes clearer as the days unfold.

Emma forms a bond with Evan, the neighbor, which offers her a sense of connection in a place that feels unfamiliar. Meanwhile, Stacey thrives socially, yet the social circle is quickly overshadowed by troubling events at school. Gracie, Emma’s new best friend, begins to display disturbingly odd behavior—she can’t stop eating and starts coughing up blood. The situation escalates when Gracie collapses outside the school; Emma runs to get help, but Gracie vomits blood on a male student in the moments before help arrives.

Media reports describe a spreading “worm flu,” adding a sense of growing danger to the town. Emma’s father goes to fetch their mother from the airport, but a government quarantine is imposed on the entire town, preventing any return home. The isolation intensifies the stakes at school and in the neighborhood.

At a party Stacey attends with Emma in tow, she discovers CJ is having sex with another student, revealing the fragility of trust in their circle. The party takes a dark turn when the ill boy from earlier reappears, now visibly sick and violently attacking partygoers. He coughs blood on Stacey, and Evan manages to shield Emma from infection. Soon after, Stacey develops a growth at the base of her neck and experiences a powerful, ravenous hunger that mirrors the spread of the disease around them.

The following morning brings a call from their father urging the sisters to secure the house as best they can. That night, the neighborhood explodes into chaos, with Mr. Toomey firing a flare gun as the military arrives, restrains him, and drags out his infected wife. The family’s secrets begin to surface: Stacey confesses that the trouble in her parents’ marriage started when she witnessed their father with a student and told their mother. She reveals that no one wanted to tell Emma, afraid she couldn’t handle it.

Evan returns, urgently pounding on the door, and soon the situation grows even more perilous as Evan’s father, Bill, appears infected and violent, breaking into the house. Evan notes that Bill has poor vision, a detail the group uses to their advantage. A chaotic struggle ends with Stacey shooting Bill, saving Emma, but she herself succumbs to a seizure moments later. In a bid to protect herself and her sister, Emma and Evan lock Stacey in the bathroom, hoping to shield her from the soldiers outside.

Drawing on lessons from her father’s science classes, Emma devises a plan to remove the parasite from Stacey’s neck. CJ arrives at the house, and Stacey pulls him into the bathroom, where she begins to devour his arm. CJ dies from his wounds, and Stacey utters, “It made me do it.” in a tearful, haunted confession. Desperate to save her sister, Emma administers drugs to knock Stacey unconscious and starts attempting to extract the parasite, but Stacey awakens and, in a horrific moment, pulls the parasite out herself.

The next day brings the government’s evacuation order for those outside the quarantine zone. Evan and Emma discover that Stacey has left the house, taking all the food with her, and they chase her into a neighboring home where a large group of the infected has gathered. Stacey declares that she can hear what the infected are saying as the parasite tightens its grip on her. With no viable option left, Emma shoots her sister to prevent further harm, and Evan helps them escape through a window as the military bombs the area to contain the outbreak.

The two survivors reach a gas station where their father had called from, finding a photograph of the family and a note on the back directing them to meet their parents at an uncle’s residence in Washington State. Evan takes a vacant car from the station, and the two set off toward a distant, uncertain hope, leaving behind the town and the upheaval that consumed their lives.