The House

The House is the primary setting for the Keys to the Kingdom series by Garth Nix. It was built by the Architect on a foundation of Nothing and exists in some fashion in all of the Secondary Realms. Time flows differently in the House than outside of it; Denizens of the House assert that the House is the only place with the correct time, as the House is the epicenter of the universe and the source from which the universe was built.

Organization
The House was originally created by the Architect. She left behind a Will stating how the House was to be governed after her time, but the Will was split into seven pieces and scattered throughout the Secondary Realms. Meanwhile, the House has been split into seven sections, each governed by a Trustee. Each Trustee also has the power to act in the Secondary Realms one day per week.

Some positions within the House, such as the Keeper General of the Front Door, can only be appointed by all seven Trustees together; other positions, exclusive to a particular area of the House, are appointed by the Trustee responsible for that area. Contracts for workers can be traded between Trustees and sections of the House in exchange for goods and services (as discussed in Grim Tuesday).

The Lower House
The Lower House is the domain of the Trustee Mister Monday, explored in the first novel in the series, Mister Monday. The Key to the Lower House takes the form of a clock hand, with the Lesser Key as the minute hand and the Greater Key as the hour hand. Mister Monday is served by Monday's Dawn, Noon, and Dusk, as well as Dusk's army of Midnight Visitors and an aged butler called Sneezer. When Arthur claims mastery of the Lower House, he creates the position of Monday's Tierce, filled by Suzy Turquoise Blue, and assigns the first part of the Will as Steward.

While there are townships in the Lower House that deal primarily with text, having occupations such as Ink-Filler (the job title of Suzy), the Lower House also contains the Deep Coal Cellar. In the Cellar, blocks of coal are mined and then shaped into precise, equal chunks. Working in the Cellar is a punishment, as workers are stripped of their names and simply given job titles while working in the cold, damp, coal-dust-filled air.

Also in the Cellar is the clock-face prison of the Old One, a nemesis of the Architect who is chained to a large clock. Every twelve hours, clockwork creatures of Nothing emerge from the clock and destroy some part of his body; at the time when he is visited by Arthur Penhaligon, the clockwork creatures devour his eyeballs every twelve hours.

The more respectable segment of the Lower House goes up at least thirty-nine thousand floors, as Suzy states that she lives thirty-nine thousand floors above the business sector that Arthur initially enters. One floor along the way contains an office modeled to look like a forest, with a window that can be programmed to look out over any piece of reality in the records.

The Lower House also contains Monday's Antechamber and Dayroom. The Antechamber takes the form of a campground embedded in the side of a volcano. It is filled with tents for Denizens waiting to meet with Mister Monday. A weirdway exists connecting the Antechamber to the Dayroom. Monday's Dayroom takes the form of a large collection of steaming mud baths, surrounded by a pit of bibliophages.

The Far Reaches
The Far Reaches are the domain of the Trustee Grim Tuesday and are the primary setting of the book Grim Tuesday. The Key to the Far Reaches appears as a set of gauntlets; although they look metallic and unwieldy, silver rimmed in gold, they fit like a comfortable pair of gloves. The Grim is served by the Grotesques, his Dawn, Noon, and Dusk who he melded into one and then broke into seven separate entities.

The Far Reaches initially contained a spring of Nothing that could then be shaped into goods for the House. However, in his greed, the Grim destroyed the spring and turned most of his domain into a giant pit to mine for Nothing. He employs indentured workers whose contracts he barters from the other Trustees and has a special train that only he and his Grotesques are allowed to ride, which goes all the way to the bottom of the Pit.

The Grim also has a Treasure Tower, encased in a glass pyramid, in which he stores a variety of special goods. Included amongst these treasures are a number of ships in bottles, each of which serves as a window to the world represented inside of it. Also among the treasures is Captain Tom Shelvocke, the ancient Mariner who is employed by the Grim to destroy intruders. Grim Tuesday's registry of indentured workers is also stored in the Treasure Tower.

The Border Sea
The Border Sea is the domain of the Trustee Lady Wednesday, the primary setting of the book ''Drowned Wednesday. ''The Key to this section of the House appears as a trident. Lady Wednesday in her leviathan form is served only by Wednesday's Dawn, with whom she communicates through coded eye movements; she devoured her Noon and Dusk in her gluttony. When Arthur claims the Border Sea, he names Sunscorch as Wednesday's new Noon and Dr. Scamandros as Dusk.

The Border Sea is a body of water within the House but apparently surrounding its borders; it can connect to any body of water in any of the Secondary Realms. It was originally entered from a small town-like area known as Port Wednesday, but when Lady Wednesday transformed, water displacement flooded the port and it is now completely underwater. The Border Sea is edged by a perpetual storm front known as the Line of Storms, which will strike down any unauthorized mortal that crosses it with lightning.

The Sea is also known for its collection of lost objects. Every object that is accidentally lost, in any Realm, eventually appears in the Border Sea. Many mariners on the Border Sea, such as Dr. Scamandros, have ventured there in search of some lost object. Objects that are deliberately misplaced or stolen, however, will not show up on the Border Sea.