Blake (played by Christopher Abbott) is a husband and father living in San Francisco. After his own father goes missing and is declared dead, he inherits his childhood home in a remote area of rural Oregon. As his marriage with his successful, strong-willed wife, Charlotte (played by Julia Garner), begins to unravel, Blake persuades Charlotte to take their young daughter, Kinsley (played by Matilda Firth), to his childhood home for a vacation. However, when the family arrives at the farmhouse in the middle of the night, they are suddenly attacked by an invisible monster. To escape the danger, they hide inside the farmhouse and seal all the entrances while the monster prowls outside. As they fearfully attempt to survive the long night, Blake begins to exhibit strange behavior, gradually transforming into an unknown monster, forcing Charlotte to make a harrowing decision: which is more deadly, the terror inside the house or the danger outside?