Trapped in their New York brownstone's panic room, a hidden chamber built as a sanctuary in the event of break-ins, newly divorced Meg Altman and her young daughter Sarah play a deadly game of cat-and-mouse with three intruders - Burnham, Raoul and Junior - during a brutal home invasion. But the room itself is the focal point because what the intruders really want is inside it.

A small, seemingly innocuous plastic reel of film leads surveillance specialist Tom Welles down an increasingly dark and frightening path. With the help of the streetwise Max, he relentlessly follows a bizarre trail of evidence to determine the fate of a complete stranger. As his work turns into obsession, he drifts farther and farther away from his wife, family and simple life as a small-town PI.