Zampanò's narrative deals primarily with the Navidson family: Will Navidson, a photojournalist (partly based on Kevin Carter); his partner, Karen Green, an attractive former fashion model; and their two children, Chad and Daisy. Navidson's brother, Tom, and several other characters also play a role later in the story.
The Navidson family has recently moved into a new home in Virginia.
Upon returning from a trip to Seattle, the Navidson family discovers a change in their home: a closet-like space shut behind an undecorated door appears inexplicably where previously there was only a blank wall. A second door appears at the end of the closet, leading to the children's room.
As Navidson investigates this phenomenon, he finds that the internal measurements of the house are somehow larger than external measurements. Initially there is less than an inch of difference, but as time passes the interior of the house seems to expand while maintaining the same exterior proportions. A third and more extreme change asserts itself: a dark, cold hallway opens in an exterior living room wall that should project outside into their yard, but does not.
Navidson films the outside of the house to show where the hallway should be but clearly is not. The filming of this anomaly comes to be referred to as "The Five and a Half Minute Hallway". This hallway leads to a maze-like complex, starting with a large room (the "Anteroom"), which in turn leads to a truly enormous space (the "Great Hall"), a room primarily distinguished by an enormous spiral staircase which appears, when viewed from the landing, to spiral down without end.
There is also a multitude of corridors and rooms leading off from each passage. All of these rooms and hallways are completely unlit and featureless, consisting of smooth ash-gray walls, floors, and ceilings.
The only sound disturbing the perfect silence of the hallways is a periodic low growl, the source of which is never fully explained, although an academic source "quoted" in the book hypothesizes that the growl is created by the frequent re-shaping of the house.
There is some discrepancy as to where "The Five and a Half Minute Hallway" appears. It is quoted by different characters at different times to have been located in each of the cardinal directions. This first happens when Zampanò writes that the hallway is in the western wall (page 57), directly contradicting an earlier page where the hallway is mentioned to be in the northern wall (page 4); Johnny's footnotes point out the contradiction.
Navidson, along with his brother Tom and some colleagues, feel compelled to explore, photograph, and videotape the house's seemingly endless series of passages, eventually driving various characters to insanity, murder, and death. Ultimately, Will releases what has been recorded and edited as The Navidson Record.
Will and Karen purchase the house because their relationship is becoming strained with Will's work-related absences. While Karen is always adamantly against marriage (claiming that she values her freedom above anything else), she always finds herself missing and needing Will when he is gone: "And yet even though Karen keeps Chad from overfilling the mold or Daisy from cutting herself with the scissors, she still cannot resist looking out the window every couple of minutes. The sound of a passing truck causes her to glance away" (pages 11–12).
Zampanò's narrative includes references to Stephen King, Stanley Kubrick, Douglas Hofstadter, Ken Burns, Harold Bloom, Camille Paglia, Hunter Thompson, Anne Rice, and Jacques Derrida to indicate that the Navidsons' story achieved international notoriety.
Many of the references in Zampanò's footnotes, however, are real, existing both within his world and the world outside the novel. For example, several times Zampanò cites an actual Time-Life book, Planet Earth: Underground Worlds (page 125).
