Meg Altman (Jodie Foster) and her daughter Sarah (Kristen Stewart) move into a new New York City brownstone following Meg's divorce from her husband. The house comes with a high-tech panic room, which was designed to be completely secure in case of a home invasion. It is equipped with CCTV cameras, a separate phone line, and multiple layers of steel and concrete.
On their first night in the new house, Meg and Sarah find themselves under attack by three intruders: Burnham (Forest Whitaker), Raoul (Dwight Yoakam), and Junior (Jared Leto). The trio break in looking for a large sum of money hidden within the house. When Meg and Sarah retreat to the panic room, the intruders become desperate and violent, trying everything in their power to break in.
As the night goes on, tensions rise within the confined space as Meg and Sarah try to stay hidden, while the intruders use everything at their disposal to get inside. However, it soon becomes clear that the panic room itself is the prize they are after. Unknown to Meg, the previous owner of the house and the panic room was a wealthy businessman who had stored a large sum of money in a hidden compartment within the room.
The movie follows Meg's struggle to survive the night and protect her daughter, while simultaneously trying to outsmart the intruders and keep the panic room's secret hidden. It is an intense and suspenseful thriller that keeps the audience on the edge of their seats throughout.