Over three months in 2020, most of Earth’s human and animal populations have been wiped out by sightless extraterrestrial creatures. The creatures have hypersensitive hearing, indestructible armored skin, and attack anything that makes noise.
The Abbott family – wife Evelyn, husband Lee, congenitally deaf daughter Regan, and sons Marcus and Beau – silently scavenge for supplies in a deserted town. While out in the open, the family communicates with American Sign Language (ASL). Four-year-old Beau is drawn to a battery-operated space shuttle toy, but his father takes it away. Regan returns the toy to Beau, who also takes the batteries his father removed. Beau activates the shuttle when the family is walking home near a bridge. The noise gives away his location to a nearby creature, which slaughters him before Lee can get to him.
More than a year later, Regan still struggles with guilt over her brother’s death, Evelyn is in the final stages of pregnancy, and Lee is fruitlessly trying to make radio contact with the outside world. Lee attempts to upgrade Regan’s cochlear implant with scavenged miniature amplifiers to restore her hearing, but the devices are ineffective. Later, Lee takes Marcus to a nearby river to teach him to fish while Regan, denied the chance to come by Lee, visits the memorial to Beau at the bridge where he was killed. Lee explains to Marcus that they are safe from the creatures so long as louder sounds mask their audible movements. When Marcus asks his father if the reason why he takes him but not Regan to learn fishing is because he blames her for Beau’s death, Lee replies no, and he blames nobody. Marcus reveals that Regan blames herself, and needs her father to tell her he still loves her. Alone at the house, Evelyn goes into labor earlier than expected. While making her way to their house attic, she steps on an exposed nail. In pain, she accidentally drops a glass picture frame and alerts a nearby creature. Evelyn flips a switch that changes the exterior house lights to red as a danger signal to the others, and struggles to remain silent during her contractions.