The House (The Keys to the Kingdom)

The House is a domain that serves as the center of the universe in the Keys to the Kingdom series by Australian author Garth Nix. Anything in creation not in the House, such as earth (the solar system and indeed this universe), is part of the Secondary Realms. The House is divided into seven demesnes; each of which is ruled by a master named for a day of the week, the Trustees, or sometimes the Morrow Days. The demesnes are, in the order Arthur Penhaligon has claimed them: the Lower House, the Far Reaches, the Border Sea, the Great Maze, the Middle House, the Upper House and the Incomparable Gardens.

Description

The House's physical appearance in the Secondary Realms is described as a vast building featuring many different architectural styles, which often appear to be brought together at random. Its physical location differs; Arthur first sees it near his own residence, and his friend Leaf sees it above a hospital. Arthur, Leaf, and Leaf's ally Sylvie are the only mortals shown to see the House, each by a different means: Arthur can see it presumably because he is the Heir of the Architect; Sylvie requires special glasses given to Leaf by the House Sorcerer Dr. Scamandros; and Leaf appears able to see it without aid. It is her belief that she has inherited powers of extrasensory perception from her grandmother, whom she thinks to have been a witch, but this has not been confirmed. A possible alternative suggests that her immersion in the House (which occurred prior to her view of it from outside) enabled her to see it.

The House has seven demesnes: the Lower House, Far Reaches, Border Sea, Great Maze, Middle House, Upper House, and the Incomparable Gardens. The Gardens are the uppermost part of the House. The Lower Coal Cellar acts as a basement; it is infinite and houses the ancient prison of the Old One.

Purpose

The divine figure known as the Architect created the House to record, without intervening on any behalf, all that happened in the Secondary Realms (a term used to describe the Universe at large). Most Denizens of the House believe that the House was created first, but this is only true of the Incomparable Gardens. Having created House, Realms, and a Law that would prevent Denizens from intervening in the actions of mortal creatures, the Architect vanished and is not shown again. The Law is not binding however (although in 'Grim Tuesday', Arthur repels two agents from the House by invoking the Original Law, along with his latent power gained from the use of the First Key); it can be broken, as all of the Architect's Trustees have done at one time or another, making themselves the villains of the story. A Trustee can only enter the Secondary Realms on their "day", i.e. Mister Monday can only enter the Secondary Realms on a Monday. Furthermore, the Superior Denizens (Dawn, Noon, and Dusk) of each day can only enter the Secondary Realms on the hour of their name (a Noon, for example, can only enter during the hour from 12:00pm to 1:00pm).

House Time is constant, while time in the Secondary Realms is malleable; it is even able to flow backwards if a sufficient power, such as a Key to the Kingdom, is used upon it. Thus, a day may pass on Earth while half a year will pass in the House. This inconsistency in time allows Arthur to spend large amounts of time in the House whilst 'Local Earth Arthur time' remains still. This occurs because the Front Door (the main method of transit between the House and the Secondary Realms) takes note of important people's travel (e.g. Arthur's passage through the Door) and alters the time it allows passage back accordingly. The system is not infallible; while Leaf is in the House, time continues as normal in the Realms (Sneezer states that the Door did not consider Leaf noteworthy enough to account for). This temporal system is not dissimilar to that used in the Chronicles of Narnia, wherein lengthy adventures or even lifetimes can be spent in Narnia's world while only seconds pass in ours.

Denizens

Denizens are the original inhabitants of the House. Denizens are ranked within the House in an order of Precedence, but the current hierarchy of ranking is unknown. A Denizen's social status, political role, and magical power appear to be synonymous, in that magical power over an item is given or taken in the same way as if it were political power.

Denizens are similar to humans in all aspects but these:

• The blood of a Denizen is blue with two unexplained exceptions, while the bones are golden.
• Denizens are very resistant to change of any kind, and are often described as narrow-minded or stupid.
• Denizens are naturally good-looking. Additionally, if a Denizen’s House Precedence is high, he or she is better-looking and taller than Denizens of lower precedence.
• Denizens are nearly immortal:
  • Denizens cannot die of old age, sickness, dehydration, or starvation while in the House, and will eventually heal from almost any injury, including decapitation. Denizens normally value sicknesses from the Secondary Realms. If the body is destroyed, they can slowly grow a new one, though they can be prevented from doing so. The ability to survive without food or drink while within the House, as well as not dying from old age, extends to Mortals and Piper's Children, although the resistance to injury does not.
  • Denizens can only be killed by
    • Fire, superheated steam, or other sources of extreme heat;
    • Certain weapons (such as the Commissionaires’ Clubs and various weapons used by the Glorious Army of the Architect);
    • A prolonged absence of their heads; without sorcerous intervention
    • Nothing;
    • A festering bite or scratch from a Nithling, which dissolves them into Nothing;
    • A Key;
    • Drowning (although, this does not completely kill them immediately); and
    • Falling from at least 15,000 feet.

Demesnes

The Lower House

The Lower House was the domain of Mister Monday. Due to Monday's affliction with sloth, its bureaucratic affairs became impossibly inefficient until Monday's loss of power, after which Dame Primus, as the Steward of Arthur's regime, has attempted to make the Lower House manageable. The remaining Morrow Days have attempted to impede this effort by swamping the Lower House with paperwork.

The Lower House is guarded by the Corps of Inspectors, by the robots known as Metal Commissionaires, by Denizen Commissionaire Sergeants, and by Midnight Visitors. These are under the control of the office of Monday's Dawn, Noon, and Dusk, respectively.^[1]

Doorstop Hill, and on it the Front Door of the House, is located in the Lower House. The Front Door of the House is a means by which one may leave the House and enter a Secondary Realm, and vice versa. To enter it from the Secondary Realms, one must be able to see the House. It is a pair of wooden doors surrounded by constantly shifting wrought-iron patterns whose movements are mesmerizing to human eyes. The Door is guarded by the Captain Keeper; in his absence, the Lieutenant Keeper of the Door, an ally of Arthur's, has guarded it ever since.

The Coal Cellar is a deep pit in the Lower House where Denizens that have been punished are sent to mine and shape coal for delivery to buyers within the House. The Old One is also imprisoned here. He is bound by two chains extending from a minute and hour hand on a clock face. When both hands reach twelve, two clockwork figures appear and gouge out his eyes. This is the punishment laid upon him by the Architect for his attempting to interfere in the Secondary Realms, which was directly forbidden by the Architect. His escape is impossible; according to Monday's Dusk, the Seven Keys combined could not free him. In Lady Friday, Dr. Scamandros mentions that something odd is happening in the Coal Cellar; not with the Old One, but the collectors. The nature of what is happening is not stated. It is revealed in Superior Saturday that flowers have started growing around the Old One's clock-face prison, and that his clockwork torturers have been destroyed by the Old One and that he will soon be able to escape.

The Seven Dials is a set of seven grandfather clocks in a room accessible from Monday's Dayroom, the main office of the Lower House. Using them, one can travel to the current time in any given Secondary Realm. Thus far, only Sneezer, Monday's butler, has operated them. When the Lower House was consumed by Nothing, Dr. Scamandros says that the Seven Dials would move themselves to safety, but did not reveal where they had gone.

Nearly all of the Lower House was destroyed by Nothing that had leaked from the dam in the Far Reaches, being unleashed by Superior Saturday. The bulwark between the Lower House and the Far Reaches only lasted a few hours, during which important records and some Denizens were saved. However, the bulwark eventually collapsed and the Lower House was devoured. Only part of the Deep Coal Cellar survives, due to the protections around the Old One's prison; but it is slowly dissolving as the prison weakens.

The Far Reaches

The Far Reaches was the domain of Grim Tuesday. Originally, the Far Reaches was a Grand Cavern, and in the Cavern was a steady spring of Nothing. Tuesday used the Nothing to create items, such as Commissionaires and Not-Horses, which he sold to other demesnes of the House. His avarice, however, drove him to deepen and widen the spring in an effort to find more Nothing. In time, the spring became a vast Pit, which eventually becomes the whole of his demesne, sparing only his Treasure Pyramid and the train station where his personal train into the Pit docks. Grim Tuesday used indentured slaves from his own demesne, as well as ones from other Morrow Days sent to him as payment, to mine the useful amounts of Nothing. The Pit is extremely dangerous as it has been dug deep into the foundations of the House and is very close to breaching into the void of Nothing beyond. After Grim Tuesday was deposed, Dame Primus received regency over the Far Reaches and ordered their Denizens to fill the Pit, but was unable to have this task completed before the Far Reaches were destroyed by a wave of Nothing released by Superior Saturday. The entire demesne was consumed by the wave of Nothing in four to five minutes. The Immaterial dam wall was breached by sourcerous drills. During the interim before this event, many of the things produced by Grim Tuesday for the other demesnes had become scarce as a result of the cessation of production caused by Dame Primus' orders.

The Border Sea

The Border Sea was an ocean previously under the rule of Drowned Wednesday. After Wednesday transformed into a leviathan and submerged into the sea, the sea overflowed nine-tenths of all land in the demesne including Port Wednesday. A new port was partially prepared on Wednesday's Lookout before this deluge. Any of the buildings that were submerged were transformed into ships, which thereafter sailed the Border Sea along with Wednesday’s original fleet of 49 ships. A unique aspect of the Border Sea is that anything that is lost accidentally, but not stolen, will appear in it.

The Border Sea extends into any body of water in the Secondary Realms, and therefore can be a means of travelling anywhere. The Line of Storms, a series of vicious lightning storms, guard the entrance into the sea; only an express invitation into the Sea will prevent the Line from killing people instantly.

Raised Rats live here and pilot their steamships. Pirates also live here, of whom the most formidable was a mortal pirate who somehow passed the Line of Storms into the Border Sea, Elishar Feverfew. Feverfew was a trained House sorcerer, and was trained in several dark arts. He used Nothing very indiscriminately and had been changed by this Nothing into something not quite human or Denizen.

At the end of Drowned Wednesday, Wednesday’s Dawn informed Arthur that much of the Sea had extended into the Void of Nothing, and since Wednesday used all of the Key’s power keeping her shape, had not reined it in. As Arthur does not wish to use the Keys unless absolutely necessary, he left this task to his Steward Dame Primus. In Lord Sunday, the Sea is revealed to be destroyed by a wave of Nothing.

The Great Maze

The Great Maze is a demesne that was ruled by Sir Thursday. It is a gigantic, chessboard-like arrangement of one thousand by one thousand terraformed tiles, whereof each is one mile long and one mile wide. At each sunset the tiles change their locations, allowing any attackers to be split and easily attacked by the Glorious Army of the Architect; a means known as Tectonic Strategy. There are several fixed tiles, such as the Citadel, Fort Transformation, and a few others. The Citadel is the main Headquarters of the Maze, where Thursday himself makes his residence, and Fort Transformation is where new recruits spend a year of training before going on to serve the last 99 years of their tenure in one of the various factions in the Army.

Tile 500/500, one of the four central tiles, is the “master tile” of the Maze, in that no other tile may move its location unless this one is unhindered. Therefore to fasten it in place (as in the novel Sir Thursday) is to render the Maze immobile.

At one end of the Maze is a mountain range. Within this range is a tunnel that connects to the Void of Nothing, by which controlled amounts of Nithlings are allowed into the Maze so that the Army may fight them. There are four gates within the tunnel; one gilded in gold, one in silver, one in bronze, and finally an Immaterial gate, the “Cleargate”. Each gate is operated by a single lever in the Border Fort above the tunnel. The gates are opened in various ways depending on the amount of Nithlings Sir Thursday wishes to be brought into the Maze.

During Sir Thursday, all four gates were opened against rules, whereupon a vast, uncontrollable amount of Nithlings entered the Maze. Unlike the Nithlings Denizens are used to fighting, these Nithlings are smart, organized, and near-Denizen in their attributes. It is revealed that these Nithlings are under the command of the Piper. The New Nithlings then took control of the Border Fort, and kept the gates open past when they were to be closed, allowing huge numbers of New Nithlings to enter.

After the deposition of Sir Thursday, the New Nithlings still controlled much of the Maze, despite their losses in a battle against all Denizens loyal to protagonist Arthur.

As of Superior Saturday, the Citadel became the base of Arthur's operations in the absence of the Lower House and Far Reaches. When the New Nithlings damaged the mountain wall that barricaded the Maze from the Void of Nothing, this put the Maze in danger of dissolution.

During Lord Sunday, the Glorious Army of the Architect flees to the safety of the Middle House after Dame Primus was unable to deal with the damage to the mountain shield. Suzy appears and quickly is whisked away by a rearguard led by Marshal Dusk as Nothing dissolved the Citadel. Later when Leaf became Lieutenant Keeper of the Front Door, she sensed the Great Maze collapse into the Void.

The Middle House

The Middle House is a giant, thrice-terraced mountain consisting of three large plateaux previously under the control of Lady Friday. The plateaux are connected by the Extremely Grand Canal, a waterway whose water transports any writing to its desired destination. The workers of the Canal wear clothes made of out of paper covered with writing so that they float if they fall into the water. In Lady Friday, due to Friday's obsession with experiencing, it became thoroughly wintry.

Each of the plateaux, or “shelves”, serves a different function. The bottom, and the largest, called the Flat, is location of the Guild of Gilding and Illumination and of Letterer's Lark. The next shelf, the Middle of the Middle, houses the Guild of Illustration and Augmentation. Finally, the Top Shelf has the High Guild of Binding and Restoration. In between the Top Shelf and the crest is a crack in the mountain leading to the Eyrie of the Winged Servants of the Night, which included the former prison of the Fifth Part of the Will.

On the very crest of the mountain is Lady Friday’s Scriptorium, where, in Lady Friday, she leaves a replica of her Key, in hopes of killing Arthur, the Piper, and Saturday. This trap, although it failed, opened onto the Void and managed to destroy the entire Scriptorium and a good portion of the mountain top; however Arthur, using all of the four Keys under his control, managed to stop the void but was unable to fill the gap it left behind.

At the end of Lady Friday, Arthur granted Dame Primus Stewardship of the Great Maze and the Middle House, although he retained the Fifth Key.

In Superior Saturday, the bulwark between the Middle House and the Lower House was weakening due to erosion caused by Nothing. The Lower House and Far Reaches had been destroyed when the Pit was breached and the two demenses were consumed by the Void of Nothing. Dame Primus is told that a geyser of Nothing has sprung nearby Letterer's Lark and, upon Arthur's insistence, spilts into two parts, Dame Quarto and Dame Septum; one to deal with the bulwark of the Middle House, now the only protection of the Middle House against the Void, and the other to repair the mountain barrier of the Great Maze. Towards the end of Lord Sunday it is consumed by the void.

The Upper House

The Upper House was ruled by Superior Saturday. It is in the Upper House where House Sorcerers are trained. The Upper House consists office units on moveable scaffolding, which Piper's Children are employed to maintain and move as directed. In Lady Friday and Superior Saturday, Superior Saturday tries to stop the phone connection to the Lower House, the Far Reaches, the Border Sea, the Great Maze and the Middle House, but is unable to do so because the metaphysical wiring falls under the authority of the Far Reaches and the phone operators are located in the Lower House.

This demesne is in perpetual rain, due to the fact that the Sixth Part of the Will was broken up into type and dispersed into the water. The Denizens working here have umbrellas to stop the water, but these are sometimes ineffective. Higher Denizens also collect water and let it drop in waterfalls on their inferiors. This enabled the Will to communicate with Arthur. The papers they work on stay dry despite the rain.

The ceiling of the Upper House is actually the floor of the Incomparable Gardens and is shrouded usually in clouds. Sunday constantly taunts Saturday by parting the clouds only for her, exciting her envy. Saturday, for almost ten thousand years, has been building a tower with her private viewing chamber at the top while the other floors are slotted in below. The purpose of the tower is to reach and invade the Incomparable Gardens above and claim it for herself. Within the Upper House are four large Drasil trees located at the four corners of the Upper House that are constantly growing at a rate faster than Saturday can build her tower. As these trees grow, the Incomparable Gardens move further upwards. The tower is seventeen thousand feet high, and the Denizens that work in the tower all have different coloured umbrellas which can be used to determine the part of the tower in which they work. The basic building blocks of the tower are wrought iron cubes with a grille floor and no ceiling.

In order to stop the trees from growing, Saturday engineered the destruction of the Lower House and Far Reaches with the use of sorcerous drills that destroyed the dam wall of the Pit in the Far Reaches. The Nothing devoured the two demesnes, cut off the trees' lowest roots, and therefore stunted their growth by 6%; enough to permit invasion.

In Lord Sunday, the assault by Nothing on the bulwark of the Middle House destroys the main roots of the Drasils, and the Incomparable Gardens falls about a hundred metres into Saturday's Tower. It is then destroyed when a wave of Nothing created by the Architect's Will's completion destroys it.

The Incomparable Gardens

The Incomparable Gardens are Lord Sunday’s demesne. It is supposedly the most beautiful garden in the Universe, and is guarded by a variety of insectoid Nithlings resembling oversized worms and beetles. Dame Primus mentions that Denizens of this area of the House would be immediately noticeable in the Great Maze. The floor of the Incomparable Gardens is the roof of the Upper House and is constantly rising thanks to the four Drasil trees which support it and grow to raise it. The branches of the trees attack anyone who comes near, and beetle-like Nithlings guard the trunks of the trees. It has been revealed by the Sixth Part of the Will that the Incomparable Gardens, rather than the entire House, is the Epicenter of the Universe and therefore essential to the universe's survival.

At the end of Superior Saturday, Saturday breaks through the ceiling and reaches the Gardens, emerging into a croquet lawn. During Lord Sunday, a fierce struggle ensues between Sunday and his legions of insects and troops, and Saturday with her army of Sorcerous Supernumeraries and other dangerous foes. The Piper, fleeing from the onslaught of Nothing which annihilated the Lower House, the Far Reaches and the Great Maze, is hot on her heels. Arthur and the Glorious Army of the Architect, which now contains every Denizen under the command of Arthur and Dame Primus, take refuge in the Middle House before launching a surprise attack on Saturday's tower which breached the floor of the Gardens. They are trapped between the Piper's Newniths and Saturday's reinforcements, which flood into the Gardens to join the fight.

The Elysium, where Sunday makes a stand against the invading forces, was the first place to emerge from the Void, along with the Architect. The Seventh Key is strongest here, able to sense approaching troops and create natural disasters to halt them. It is possible that the Incomparable Gardens represent the Garden of Eden.

Transportation & Communication within the House

The Front Door

Controlled by the Captain and Lieutenant Keepers of the Door, the Front door is a huge three mile wide/tall dome. Every inch of the walls are filled with portals to parts of the house, for example the Upper House. Some protude into the Secondary Realms and the Void. In Lord Sunday, Leaf becomes Lieutenant Keeper, and senses the Void exploding through many of the entrances. She is there when the Great Maze collapses onto itself and the Realms are infected. The entrance to the Front Door takes the form of a huge door a hundred metres high and fifty metres wide. From the start of Mister Monday, trouble occurs inside the Door. Superior Saturday, self proclaimed superior sorceror, sends her Dusk on many occasions, mostly through the Front Door. She sent him to kill Suzy and destroy the Border Dam in the Far Reaches. Access to the Front Door is restricted, allowed only where the Door flows, like a huge ocean. Looking too much at the Door causes blindness and intense madness, such things may have happened to the Piper and some nithlings. One of the side portals is Monday's Postern, which catapults the receiver straight into the Door. In Grim Tuesday, the Lieutenant Keeper sends Arthur to the Far Reaches to overthrow Grim Tuesday and gain sovereignty over the Far Reaches. He also sends Leaf to the Great Maze, as well as Suzy.

Wings

Wings are an everyday means of short-distance travel within the demesnes of the House. When used, they most often take on an angelic quality (i.e. white and feathered), but can have other appearances. Monday's Noon's wings are described as "white and lustrous" but stained with dried blood,^[2]:84Monday's Dusk's wings are black and "as glossy and dark as a raven's",^[2]:201 and Pravuil uses wings that are yellow.^[2]:312

There are also different types of wings. Cheaper, paper-made wings are disposable, and are made for temporary use. They are unidirectional (up or down) and the user can only partially control them by leaning in the desired direction.^{[3]:131[3]:132} Higher-quality wings can be taken on and off at will and are controlled by telepathy. Some of the higher-quality wings have special properties, such as the ability to shed light or generate invisibility in the Secondary Realms. Wings are banned in some areas of the House because of various air-borne hazards. In the Pit in the Far Reaches they attract Nothing from the clouds and this Nothing often forms flying Nithlings.^[3]:2 Monday's Dayroom has a protective system against intrusion by fliers, in that superheated steam is shot at anyone who tries to fly over head. In the Upper House, Drasil branches invariably destroy any users of wings who fly above a certain height, however Saturday is able to circumvent this by using sorcery to repel the boughs.^[2]:297 In the Great Maze, wings attract lightning (which is somehow related to the tile movements).

Postage Service

The House has an internal postage service, but this appears to be notoriously poor. Letters take weeks, or sometimes years, to reach their destination; most do not reach at all. This is due mainly to the disorder in the Lower House and has apparently grown worse prior to Mister Monday's downfall, having all the letters and newspapers cut off completely in some of the House, according to Piper's Child Fred Initial Numbers Gold. It is revealed in the fourth book that if a Denizen does not accept the military draft offered him, the Denizen will be turned into a brown-paper-wrapped parcel and transported through the postage system to the Great Maze.

Elevators

Elevators are currently the easiest way to travel between the demesnes of the House, save the Fifth Key, which lets the user go to any reflective surface in existence if its user has been there by another means. As the elevators fall under the authority of Superior Saturday, they are banned from the realms controlled by Arthur as of Lady Friday. The size of an elevator can vary greatly; it can be the size of a telephone booth or of a football field. When the elevator is in motion, its path is marked by a beam of light. In the Border Sea, elevators can only travel to Port Wednesday, as the rest of the realm is submerged. The elevators can be controlled by either the elevator's operator, Superior Saturday, or (probably) Lord Sunday.

Weirdways

Weirdways are pathways that exploit the veins of Nothing within the House. One is able to go through the Nothing via a dark corridor with soft and jellylike walls, floor and ceiling. Weirdway entries are often disguised as innocuous items within a room, such as a painting or coin on the floor or a clock, and they cannot be moved. According to Suzy Turquoise Blue, only the blood of one of the Morrow Days can close a weirdway.

Transfer Plates

Large discs that work as a sort of teleportation throughout existence. Transfer plates are usually electrum or (more rarely) fine china. Touching a transfer plate, intentionally or not, will automatically transfer a being to the prescribed destination of the transfer plate. The plates can be controlled by Superior Saturday.

The Improbable Stair

The Improbable Stair is a stairway that can traverse all of creation. It was the Architect's personal transport by which she visited all of her work. To enter the Stair, one must first have an item of power, such as a Key or the Piper’s Pipes. The traveler must then see a resemblance to a stair in any object, such as a bent blade of grass or jagged crack in a surface, and imagine the presence of a true stairway. There are several landings on the Stair, of which all open seemingly at random onto a place and time. Having reached a landing, the traveler must return to the Stair by the mentioned process. The entire use of the Stair is described as risky and dangerous, and these risks increase when the destination is near Nothing. Some Denizens cannot travel on the Stair (the reason for this is unknown); but Piper's Children are always accepted.

The Improbable Stair has been used five times:

• Arthur Penhaligon and Suzy used the Stair in Mister Monday to travel from the Coal Cellar to Monday’s Dayroom.

• Sir Thursday uses the Stair in Sir Thursday to reach square 500/500 to destroy the giant spike of Nothing which was built by the Piper to freeze the squares in the Great Maze. He takes with him Arthur, Suzy, Fred, and nine other children.

• The Piper uses the Stair in Lady Friday to get himself to a safe place when a trap disguised as the Fifth Key opens into the Void of Nothing.

• Arthur, Suzy, Fred, and the Fifth Part of the Will use the Stair near the end of Lady Friday to quickly get back to Monday's Dayroom.

• Arthur uses the Stair in Lord Sunday to save himself after falling off Saturday's tower, and again to escape from a dangerous planet of battling insectoids.

Telephones

Telephones are a means of communication within the House, and also to the Secondary Realms. The ring is inaudible to mortals, save Arthur and Leaf. House telephones resemble an early form of terrestrial telephone, and seem to work in the same fashion, in that they require an operator. During Lady Friday, Superior Saturday attempts to prevent Arthur from using them; but as they fall under the authority of the Lower House, and their wiring under the authority of the Far Reaches, she has limited success. The telephone operators are especially willing to connect Arthur, as he is the only one to give them the courtesy of saying "please".

The Fifth Key

Lady Friday's Mirror, the Fifth Key to the Kingdom, allows the user to summon a portal to any part of the House or the Secondary realms coming out through a reflective surface, most commonly a pool of water or a mirror on the wall. The places the mirror can access are limited to locations that the wielder has previously visited by other means. Presumably, this limitation extends to Arthur, the new master of the Fifth Key after the events of Lady Friday, as well.

The Lieutenant Keeper's Sword

Albeit restricted to the Front Door, the sword pulls the holder to wherever they need to go. For example, Leaf needed to check up on the Secondary Realms and was pulled at full force through the interior of the Door. However, the sword attaches itself to the Lieutenant Keeper and cannot leave the Door unless powerful sorcery is used on it.

References

1. ^ Mister Monday, Garth Nix
2. ^ ^{a b c d} Nix, Garth. Mister Monday. First ed. New York: Scholastic Paperbacks, 2003.
3. ^ ^{a b c} Nix, Garth. Grim Tuesday. First ed. New York: Scholastic Paperbacks, 2004.