Samira “Sam,” a pessimistic cancer patient with a terminal diagnosis, lives in a hospice outside New York City with her cat, Frodo. Despite her reluctance, Sam is persuaded by Reuben, a nurse, to join a group outing to see a marionette show in Manhattan. While in the city, the group witnesses meteor-like objects descending from the sky. Soon after, hostile extraterrestrial creatures launch an attack on the gathered crowd and passersby. When a creature strikes a noisy ambulance, the ensuing explosion renders Sam unconscious.
Sam awakens later inside the puppet theater, finding herself among other survivors, including Henri, who quietly signals her to stay silent. Military helicopters overhead broadcast warnings, instructing civilians to remain hidden and silent until rescue efforts can commence. Sam watches as fighter jets destroy the bridges leading out of Manhattan, trapping the creatures on the island. In a moment of panic, one of the survivors becomes hysterical, and Henri accidentally kills him while trying to keep him quiet.
Later that night, the power grid fails, causing the building’s emergency generator to activate loudly. Reuben manages to turn it off, but the noise draws a creature, which kills him when it hears his shirt tear. Overcome with grief, Sam takes Frodo and heads toward Harlem. The military announces plans to evacuate civilians by boat from South Street Seaport, as the creatures cannot swim. As groups of people leave their shelters and head toward the evacuation point, the noise from the crowd draws the creatures, leading to a deadly stampede. Sam runs in the opposite direction and is separated from Frodo in the chaos.