When Meg Altman (Jodie Foster) and her teenage daughter Sarah (Kristen Stewart) move into a luxury Manhattan townhouse they have no plans to use the ultra-secure panic room installed by the previous occupant. However, during their first night in their new home, three burglars break in hoping to steal the money they believe is still concealed in the panic room's safe.

Meg and Sarah quickly take refuge in the secure chamber, locking themselves in and watching the burglars through the surveillance system. What follows is a tense game of cat and mouse as the criminals attempt to unlock the room and the mother and daughter try to signal for help.