Windowless Building

The Windowless Building (窓のないビル) is a tall building that is literally windowless; located in School District 7, it is the main base of the General Chairman of Academy City, Aleister Crowley, and the prison of Fräulein Kreutune.

It is later revealed that the Windowless Building is also a spaceship, built to allow Aleister to reach the stage of space as part of his plan.

Exterior
The Windowless Building is located around the middle of the city, at the center of School District 7. As its name suggests, the building contains no windows, corridors, stairs, air ducts and no sign of a visible entryway.

In the anime and manga adaptations, the building is a white colored structure, several stories in height with spires and aerials jutting out of the top. During the night, purplish light covers the building giving it an eerie glow compared to the surrounding buildings in the area.

In the light novels, the building is also a white colored structure, over 100m tall and several stories higher than the surrounding buildings. Unlike the anime and manga versions which have largely straight outer edges, its outer edges curve inwards towards the top.

There is a large space below the Windowless Building with ramps leading in and a set of rocket engines, indicating the building's nature as a spaceship and the plan for it to leave the planet.

Aleister's Chamber
For most of the series, the only area inside the building which was directly shown was the quadrangular chamber where Aleister Crowley resides. The chamber's walls and ceilings are covered with tubes and pipes. The room is described as chilly, despite the lack of ventilation. The room's most notable feature is the single glass cylinder that usually houses Aleister Crowley, connected to his support system, housing several wires and cables, and filled with red fluid which tints the room with its color. Various floating displays are often present in the room.

Non-Euclidean Space
The interior of the Windowless Building, as viewed on December 11th when Kamijou Touma's group entered it through the hole created from the damage to the rocket boosters, is comprised of a fully enclosed environment with a strange spatial structure which surpasses Euclidean geometry. Resembling a pit or vertical tunnel leading to outer space or another dimension, it doesn't correspond to the building's outer dimensions, reaching up kilometers or tens of kilometers, on a scale which is usually only found in mountain climbing.

The length and width of the interior is about the size of a school gym, with no internal walls, however the ceiling is not visible from the base. As one ascends the structure, the bottom is soon shrouded in darkness as well. This non-Euclidean space doesn't have floors, however it can be divided into regions based on the changing means for ascending the structure.

In the lower levels, there are stairs with railings which are attached to the inside of the building's outer wall and spiral upwards. There is also an escalator and a small open elevator similar to those found on a construction site or in mines. There are various paths which branch off up and down at several landings, however it all ultimately lead in the same direction.

In the next region up, with the bottom no longer visible, the stairway, escalators and elevators give way to narrow metal ladders which are directly embedded in the wall with narrow catwalks and walkways with metal lattice floors. This in turn gives way to silver ducts which twist around like snakes and air conditioners attached to the wall which stick out like univalves on a rock climbing wall - a cliff face with no clear path.

After this region, there are no fixtures anchored to the outer walls to provide stable footing. Instead, there are window cleaning gondolas, ropeways and crane hooks hanging down from wires. These are eventually followed by fake stars and moons, of the fairy tale five-pointed and cradle-like crescent kind, about a few meters across and exerting artificial gravity.

Beyond the fake stars and moons, thousands or tens of thousands of meters up, there is a tunnel modelled after a black hole, with something like a black galaxy swirling around as if to indicate a presence on an even higher level. Jumping towards it sends one further up in a manner that feels like an elevator traveling through a tube. At the end of this tunnel is a spiral stairway, not made out of stone or metal but seemingly made of smooth porcelain or glass. If one is allowed to proceed, as they climb further, the stairs become more transparent with each step, gradually fading away and then finally vanishing.

At the summit, there is an area at the building's intended destination, seemingly in outer space with the planet spread out below them. While one can stand and function unlike in the standard environment of space, the area has no visible floor or stairs.

The non-Euclidean space is largely dependent on the building's closed-off internal environment and if that condition collapses, one can expand their perception and focus on the external scenery to dispel the fantastic scene inside the building and reveal the true form of the temple. In this case, where the final spiral staircase would have been, there is a space of steel and rare metals, lined with computers the size of industrial refrigerators and countless thick cables crawling along the floor. Where the summit would have been, there is an artificial space full of crude machines, large but giving a cramped impression.

Principles
As the base of the infamous magician and chairman of the city, Aleister Crowley, the Windowless Building has formidable capabilities that serve its purpose in protecting its sole occupant. The building is not open to the general public and is constantly protected by strict security. Since there are no entrances into the building a teleporter is required as a guide into the building. The building can produce its own oxygen, and is designed to be able to withstand nuclear attacks. Musujime Awaki also claims that it can block radiation from space, and she theorizes that the Windowless Building has other defenses inside, as she is certain that Aleister would not create such a formidable building, only to make it accessible to any teleporter with the skill to enter it.

The foundation of the Windowless Building is 15 meters below the surface, spreading out for 3 kilometers in every direction, with several thick pillars that head deep underground. Thor assumed that even with a nuclear landmine, it wouldn't be enough to take it down.

Buildings such as shopping malls and hotels are built around the Windowless Building. The area around it is design to modify the surrounding ley lines, such as the colors of the signs and lights all being uniform. It is also presumed that not only the lights and signs are arranged, but the locations and heights of the buildings are controlled in a fashion to fully control the flow of people through the area, and done in a way that it would be noticed on first glance.

Being a spacecraft, the Windowless Building has a set of rocket engines at its base, as well as a large space below it with ramps leading into it. Its exact propulsion method and capabilities as a spacecraft are not fully known, but it can be assumed that it is fully capable of leaving the planet and reaching outer space as it was intended to do.

The Windowless Building is connected to and controls many of Academy City's core functions and systems. These include the UNDER_LINE network used by Aleister to monitor the city and the network of artificial nerves and blood vessels under the city which can be used to gather the powers of the city's espers for the purposes of summoning Aiwass.

Several of the computers present within the upper parts of the building, the size of industrial refrigerators, contain grimoire information in storage in the form of plain text without encryption or encoding.

Calculate Fortress
Calculate Fortress is the mysterious material that the Windowless Building is composed of. It is apparently strong enough to protect the building from a nuclear strike and remain unscathed, and is able to withstand, without a scratch, an attack from a concrete wall-turned projectile that Accelerator threw at it using five minutes worth of earth's rotational momentum (an entire building in the anime). Despite the power of the latter, Aleister Crowley could barely feel the attack, and the vibrations didn't even shake the liquid that he was floating in.

Aleister's Chamber and Life Support System
Aleister's room appears to be quite advanced, having numerous display screens that seem to appear out of and float on air, which he can operate using the movements of his eyes and fingertips. From here, he has access to the various core functions and systems of Academy City, both open and secret. This includes a connection to the UNDER_LINE as well as other monitoring devices that go well beyond that of Academy City, such as those that allow him to monitor the Sisters' status across the globe.

The single glass cylinder in the room, connected to Aleister's support system, is filled with a red alkaline recovery fluid which penetrates into his mouth and nose, causing chromatid interference in every cell.

The support system prevents traces of Aleister's  force from escaping into the outside world and being detected from parties such as Necessarius, who were only able to detect his wavelength after he stepped outside of the building to try and kill Fiamma of the Right. Its usage also extends his overall span, giving him around 1700 years of extra time. Additionally, it also kept the many possible versions of Aleister which he had brought forth and bound within his body contained, though once he stepped out of it he started to branch out, eventually releasing the alternative selves into the world.

Prior to September 30th, Heaven Canceller was capable of shutting down Aleister's support system remotely, and was seemingly the only one that had access to a means to kill Aleister. After Vento of the Front's defeat and their subsequent conversation, Aleister removed Heaven Canceller's way of doing so.

Reading Thoth 78
The Reading Thoth 78 is an artificial intelligence and parallel processing device built into the Windowless Building, intended to verify whether Aleister's adjustments to his plan are correct or not. The core of the Reading Thoth 78's thoughts are made up of the 78 Tarot cards created by Aleister himself and through this compilation, it is also an original grimoire named the Thoth Tarot.

The Reading Thoth 78 is capable of simulating and recreating individuals, and Aleister chose to have it recreate Mina Mathers as a reminder of his trauma.

Fräulein Kreutune's Prison
Fräulein Kreutune's prison, presumably in a separate section of the Windowless Building from Aleister's chamber, is intended to keep the immortal's senses deprived in total silence and darkness, preventing her from becoming curious and breaking out to pursue new information, which would lead to her learning and subsequently transforming, all the while unable to be harmed, becoming a threat to Aleister's plan and maybe even mankind.

Conditions
The Windowless Building is intended to carry Aleister to outer space as part of his plan, however it is capable of granting him access to that stage even if it is immobilized and unable to launch. Within the fully enclosed environment, the building's interior takes on form with a strange spatial structure which doesn't follow Euclidean geometry. With the building unable to escape the planet, the internal space is extended to connect to the destination coordinates instead. Not corresponding with the building's outer dimensions, the vast vertical tunnel is on a scale usually only found in mountain climbing, reaching upwards kilometers or tens of kilometers.

This height is not a distance which human legs could normally clear in a day, however as this is an alternate dimensional space where Euclidean geometry doesn't apply, the distance of steps taken don't necessary match up with the distance actually travelled. With the giant outer walls, no view outside, and the ceiling or floor being shrouded in darkness for most of the way up, there is little to judge distance by and know for certain how far one has travelled up the structure. The air doesn't get thinner or colder further up the structure, with the temperature, pressure and humidity likely being kept at a certain value.

This non-Euclidean space is largely dependent on the fully enclosed environment of the Windowless Building. If that condition collapses, for example if the outer wall was breached, it is possible for one to focus on the external scenery and expand their perception to dispel the fantastic scene inside the building and reveal the true form of the temple. The conditions further in, at the 'summit', can be sustained to a certain degree even if the conditions collapse in other parts of the temple. In Touma's case, it required further damage to Aleister's structure and Aleister himself being knocked out.

Ascent
Though the internal space doesn't seem to follow conventional logic and lacks the conventional walls, floor and typical means of ascent present in normal buildings, it does have a variety of fixtures and features which can be used to ascend the structure. There are a lot of paths present, particularly in the lower regions with paths branching off both up and down, however they all ultimately lead in the same direction, upwards, like being set on a single predetermined path. Though that path is somewhat hazardous, the set-up is such that a fairly smooth ascent is possible (though removing a single element would leave climbers stuck), like a form of training to be completed in advance of arriving at the top.

The fixtures and features change the further up the structure one goes, and subsequently the means and the methods of climbing change as well. In the lowest regions, it is fairly straight forward to ascend with escalators, an open elevator and stairs with railings (though in the case of Kamijou Touma's group, there is also enough room for the chain beasts to properly form). Further up, with the ladders and narrow catwalks, the available footing decreases and the path becomes more precarious (also preventing the chain beasts from forming properly), requiring more care to avoid falling.

With the silver ducts and air conditioning units built into the wall, there is no longer a clear path and one has to effectively tackle a cliff face, choosing steps to climb up and around on, jumping from one to another like a real- retro platformer. In some places, the footing branches apart in positions where one clearly cannot stand. Beyond this, there is no longer anything solidly anchored to the wall, with gondolas, ropeways and crane hooks suspended from wires, providing unstable footing and often wobbling like a pendulum.

The fake stars and moons hanging from wires in the higher regions, as well as the mouth of the tunnel modelled after a black hole, exert a degree of artificial gravity which can be used to continue climbing. The exact method isn't known, but as it wasn't neutralized by Imagine Breaker, it can be assumed that the artificial gravity is being generated through purely scientific means. On encountering the artificial gravity, Othinus, wondering if Aleister was working to acquire even the forces of the planet, remarked that being able to convert the proper methods into any universal power was his kind of theory.

After jumping towards the mouth of the black hole tunnel, one is taken up even further in a manner which feels like an elevator traveling through a tube. The trip doesn't take long and ends at a spiral stairway looking as though it was made from smooth porcelain or glass. If one is allowed to go further, as they climb, the stairs gradually fade away, and they also disappear from the perspective of those not permitted to proceed, who remain on the stairs (which also provide footing for the chain beasts to form). The stairs completely disappear as one reaches the summit.

At the summit of the 'mountain' and the destination coordinates, there is an area with no visible floor or stairs, seemingly in outer space with the Earth spread out endlessly below. The non-Euclidean conditions still apply in this area and the environment is like the rest of the building in that one can stand and function within it, unlike the usual environment of outer space. The conditions in this area can be sustained to a certain degree, even if the outer wall of the building is breached and other areas of the temple are revealed with the collapse of the closed-off environment.

Symbolic Aspects
The Windowless Building has a number of symbolic aspects incorporated into it, which are elements in Aleister's ceremony to destroy the phases. The building's massive internal structure is designed to symbolize a mountain, with the many stairways, ladders and other features being symbols of mountain climbing made from urban materials. The chain beasts, which Aleister set after Touma's group to lead them to the Windowless Building and up the structure, represent the mountain's devilishness reaching for human karma and power binding human thoughts, which leads one to ascend the mountain. It also represents a unique third tree, separate from the Sephiroth or Qliphoth, built up from scratch. The ascent of Touma's group up this mountain and tree was a necessary element of the ceremony.

The Windowless Building's intended destination also has a number of aspects which play a role in the ceremony. Magic born on Earth is bound to Earth, being affected and limited by various factors, such as the ley lines running the ground, the direction and intensity of forces arriving from the cardinal directions and other heavenly bodies, and the actions of individuals who are quite willing to alter the landscape and environment in order to fulfill their goals. As such, Aleister thought he might achieve a ceremony of his goal if he escaped the limited possibilities of the Earth and carried it out in space, the Windowless Building being the vessel intended to bring him to this stage.

Background
It isn't known exactly when the Windowless Building was constructed. It was built with the purpose of acting as a base for Aleister Crowley, preventing him from being detected by the many magic side organizations who would want him dead for real, and also as a ship to allow Aleister to reach space in order to carry out the ceremony he wished to perform to destroy the phases, either through a standard launch or if that wasn't possible, by extending the building's interior dimensions towards space. It was also intended as an element within the ceremony itself.

At some point in the past, the building also became the prison of Fräulein Kreutune, who was confined and isolated to prevent her from accumulating information and transforming into something which might be a threat to mankind and/or to Aleister's plans.

In early July of the year before the main story, Kouzaku Mitori carried out an unsuccessful attack against the Windowless Building, which resulted in her being arrested and sent to the Reformatory, eventually meeting Kihara Gensei. The attack also resulted in the dark side's support organizations being called away to deal with the aftermath, resulting in a number of the dark side's 'services' (such as corpse disposal) being down until late on July 14th.

Deep Blood Arc
Both the building and Aleister Crowley are first seen when the latter is having a face to face meeting with Stiyl Magnus, after he is called back from England to deal with Aureolus Izzard taking over Misawa Cram School and capturing of Himegami Aisa. Here, Aleister also permits and suggests to Stiyl to use Kamijou Touma, the Imagine Breaker, to aid him in the mission, citing that he is simply a Level 0 and that he is someone that will not be able to leak information from both sides.

Kazakiri Hyouka Arc
The building is featured once during the arc, here it is shown that one requires the use of a teleporter, mainly Musujime Awaki to get inside the building, escorting Tsuchimikado Motoharu to meet with Aleister. Having taken immediate notice of Sherry Cromwell's and goes to the Windowless Building himself to berate Aleister for his lackluster effort at preventing her from getting in. Aleister does not heed Motoharu's concerns, telling him that he is aware of the intruder and use this opportunity to shorten plans as well as strengthen Kazakiri Hyouka at the same time.

After the incident is concluded Tsuchimakado Motoharu asks him if he is happy now that he is now closer to holding the key that can control the Imaginary Number District. After questioning him on giving consciousness to the Imaginary Number District Motoharu ponders Aleister's words, he realizes a part of what Aleister is thinking, and demands to know if he is making an Artificial Heaven. Before leaving, Motoharu gives Aleister advice and warning him that if he continues using the Imagine Breaker, then he should ready himself not to treat him halfheartedly, for surely, his right hand will eat his illusions alive. As Motoharu leaves him alone in that Windowless Building, Aleister tells that the world he believed in was destroyed a long time ago.

Academy City Invasion Arc
After finishing his conversation with Kihara Amata, Accelerator realizes that Academy City and the General Board of Directors are the ones pulling the strings behind Kihara Amata, and can easily pick one of them to find where Kihara Amata is. Angered by the fact that Academy City is using him, Accelerator once again uses Calculation assistance device to attack the building in his rage by throwing a wall at it using five minutes worth of earth's rotational momentum (an entire building in the anime).

In the aftermath of the invasion, Heaven Canceller contacts Aleister to object to his actions, more specifically Aleister Crowley's use of Heaven Canceller's patients such as, Kamijou Touma, Accelerator, Last Order and the clones for his plans. This has greatly strained the relationship between the two founders of Academy City. With Aleister Crowley unyielding in changing his methods, he severs his ties with the Heaven Canceller, his doctor.

Battle Royale Arc
After the events of the 0930 incident, BLOCK discovered that they may be able to challenge the will of Aleister Crowley. Their plan was to storm the Reformatory using the mercenaries and take hostage of Musujime Awaki's comrades that have been kept there as a leverage to force her to cooperate with them regarding the secrets of the Windowless Building, Aleister Crowley's base, which would then, if successful, allow them to execute their masterstroke, transport a Synchronous Multilayer Bomb into the building itself and assassinate him. Despite their preparations and actions, their plans are later foiled by the actions of GROUP.

Acqua of the Back Arc
Following the battle against Acqua of the Back, while waiting for the Underline network to be repaired, having collapsed due to the effects of the battle, Aleister looked over data concerning the Imagine Breaker and its growth in his chamber.

Ichihanaran Arc
The main objective of Kamijou Touma and Thor is to break Fräulein Kreutune from the Windowless Building. Despite having the feat of withstanding even Accelerator's georotational momentum powered-attack, Touma and Thor manage to crack the Calculate Fortress using a jackhammers after calculating the weaknesses of the Calculate Fortresses' impact diffusing abilities, and is later broken completely by Fräulein.

After Fräulein escapes and Touma and Thor regains consciousness after being attacked by Fräulein, the both of them are later tempted to go inside the hole Fräulein made, but manages to snap it out as so they can catch up with Fräulein.

Mental Out Arc
Kihara Noukan contacts Aleister Crowley in his stronghold and informs him of completing his 72nd and final request of Aleister of dealing with and eliminating groups or persons that have grew during his absence and refused to regroup. Noukan questions Aleister about his choice to fight the magic gods and debating each other feelings of emotions and romanticism as scientists. Noukan then asks that now that he has returned order to his rule as he has tasked him, he requests that he should use the power he has returned to him to destroy all the irregularities known as magic.

Salome Arc
When Misaka Mikoto attacked Kihara Yuiitsu with the Anti-Art Attachment in order to save Touma, the Windowless Building acted as a cushion and prevented the damage from spreading across the city. Not long afterwards, as Yuiitsu turned towards the building with World Rejecter in hand, Aleister came out of his safe zone and confronted her before turning to the other problems at hand.

Element Arc
While Academy City was swarmed by the Elements, Yuiitsu hid in the space below the building, waiting for Kamisato Kakeru and the Kamisato Faction to emerge. A confrontation between the two occurred in this space on the morning of December 9th and the rocket boosters were used as a final trap by Yuiitsu, forcing Kakeru to use World Rejecter with conflicting desires to protect the group from the igniting engines, exiling himself in the process.

Kamisato Rescue Arc
During December 9th and 10th, while the Kamisato Faction were being forced to go after Touma, Yuiitsu mostly remained in the space under the Windowless Building together with a number of the girls. In the 'new world', the Windowless Building's counterpart was flown into orbit by Nephthys, Niang-Niang and Kamisato Kakeru while escaping from the other Magic Gods.

Aleister Crowley Arc
On December 11th, after Aleister's magic sword impaled Tsuchimikado Maika at the city wall, Tsuchimikado Motoharu and Karasuma Fran together with Touma, Othinus and Index, were forced to break into the Windowless Building to find a way to dispel it, chased by the Karma-bearing chain beasts summoned by the sword. They managed to enter the building through the hole created by the damage to the rocket boosters. Shortly after beginning to climb the stairs in the building's outer wall, the group was scattered by an attack from Aleister himself.

Afterwards, Touma climbed through the Windowless Building's non-Euclidean space, while being shown visions of Aleister's past by the Reading Thoth 78's recreation of Mina Mathers. As he climbed the 'mountain', he reunited with the other members of the group. Ascending the final set of stairs, Touma was separated from the group again as he confronted Aleister at the building's summit and destination; outer space. During the fight, Aleister used the citywide nerve network to focus the powers of the city's espers and summon Aiwass.

As the battle between Touma and Aleister progressed, Mikoto's attack on the building with the Anti-Art Attachment and Liquid Proof Railguns caused its closed-off environment to be disrupted, enabling the rest of the group to perceive the true form of the building's interior and subsequently find what they needed to neutralize the magic sword stabbed into Maika, disrupting Aleister's ceremony and causing the summoned Aiwass to disappear, giving Touma the chance to knock Aleister out.

After Aleister was knocked out, the building was occupied by Coronzon, whose attack on Aleister blew Touma's group out through the newly created hole in the building. Mikoto caught most of them while Touma was caught by one of Aleister's alternative selves riding a flying broom.

Processor Suit Arc
Immediately afterwards, Aleister launched the Windowless Building into space via magic, using up 5 of his diffused possibilities in the process. Coronzon was unable to escape the building due to the intervention of the recreated Mina Mathers and then Aiwass, who granted Mina a grimoire to support her existence outside of the building, enabling her to escape. As the Windowless Building left the atmosphere, Aiwass and Coronzon began to fight.

Coronzon eventually managed to overcome Aiwass, who was unable to draw out its full potential due to lack of an avatar, and the demon turned the spacecraft around to return to Earth, setting it on a collision course with Academy City. However Aiwass had intentionally lost and made use of relativistic effects to shift Coronzon and the Windowless Building into the 'new world'. The subsequent impact destroyed the Windowless Building and Academy City's counterpart in the 'new world', but left the regular world unharmed.

Post-Handcuffs Arc
While Kamijou Touma and Hamazura Shiage were dealing with Kihara Hasuu in Vanishing Tunnel, Aleister Crowley visited the former site of the Windowless Building, joined afterwards by Kihara Noukan once he had done his part in the battle. The building was gone, but its foundation and original network still remained, so Aleister reacquired access by repairing the damaged and concealed portions. Then, Aleister searched for and found the location where Anna Kingsford's corpse had been preserved.

Daihasei Festival Arc
Following Misaka Mikoto's first transformation as a part of Kihara Gensei's experiment, Kouzaku Mitori brings out her fears and anger towards the city, and has her attack the Windowless Building, saying that as long as that command tower at the center of the city exists bad things would happen and someone will always get hurt. Mikoto complies and uses her new found power to make an incredibly powerful beam of electricity descend from the overcast sky, though the Windowless Building survives. Gensei calls Kouzaku that in spite of Mikoto's power, she cannot damage the building by attacking it head on. Gensei then says that her current state is that of 2% along the path of a Level 6.