Useful Spider

Useful Spider (営巣部隊(ユースフルスパイダー)) is an unit from Academy City's Disaster Recovery Committee, tasked with rebuilding the city following a major crisis.

Principles
A unit under Academy City's Disaster Recovery Committee, Useful Spider's purpose is to rapidly rebuild Academy City and restore order following a major disaster which has caused city-wide devastation. Once the primary danger is past, Useful Spider mobilizes to restore the city's infrastructure within a set time period. During such a period, such as the 48 Hours to Restore Order (秩序回復の四八時間) following the Elements and December heat wave, Useful Spider operates on special authority which allows them to temporarily rescind human rights to secure dangerous individuals or items, and carry out supposedly non-lethal suppression.

Useful Spider makes use of vehicles described as half trucks, with large beds on their backs. The front and rear wheels are powered in different ways; the rear wheels made into steel treads and the front wheels resembling countless insect legs wriggling around and digging to crawl or climb forward, working differently but moving in a way similar to the mouth of an ammonite or nautilus. The exposed truck bed has large speakers attached, as well as gun turrets equipped with high-pressure water cannons for suppression purposes. They also use helicopters, equipped with speakers and spotlights, armed with heavy machine guns positioned just inside the side cargo doors, and liquid (possibly water or gelatin) for suppression via drops.

Useful Spider also has a large number of 50cc AT carts, the size of one-person sofa, which can be used to set up a motor sharing service to aid the transportations of people and supplies.

Useful Spider's headquarters is located in the mountainous School District 21, hidden under a large-scale meteorological observatory, which can predict coming disasters. The observatory has a Doppler radar dome on top, as well as thick electromagnetic shielding to protect staff and equipment from microwaves.

Sphere
The Sphere (スフィア) is an information device distributed by Useful Spider.

As its name suggests, it is a metal sphere about 2m across which opens up in one direction like a lotus flower, becoming something resembling a planetarium with a faint layer of chemical smoke rising from its top, with hundreds or thousands of windows projected onto the smoke, forming a dome with a radius of 20-30m around the Sphere. The windows display information on other shelters, weather forecasts, which roads are blocked off, and progress for recovery work on infrastructure such as power and water, and distribution points for food and water.

The inner core of the Sphere contains a light splitting processor. Instead of using electricity, the processor makes use of the, where light-emitting particles of a single wavelength split into multiples one on entering a magnetic field. When the waves collide, they combine, and by bringing multiple lights together in the small processor, their amplitudes can be used to represent 0s and 1s. The processor is a stepping stone towards quantum computers which use light separately as a wave and a particle.

During the '48 Hours to Restore Order', Useful Spider supplied a Sphere to the shelters in the city, including Trial (裁判) (School District 7), Academy (学会) (School District 5), Charity (博愛), Prison (監獄), Health (健康), Journalism (報道), Show Business (芸能) (District 7), Hospital (District 7) and Esper.

Breath of Blessing
The Breath of Blessing (ブレスオブブレッシング) is a giant fan used by Useful Spider for suppression and clearing purposes. The fans are giant cylinders about 20-30 meters wide, carried from helicopters by wires, of the class used in wind tunnel experiments to simulate wind speeds at Mach 7, and capable of blowing down reinforced concrete and small buildings.

The fans were originally designed to designed to artificially alter wind direction and redirect toxic smoke away from densely populated areas in the event of a dangerous chemical fire in one of the city's laboratories, however this nonlethal firefighting usage was largely an excuse for paperwork.

48 Hours to Restore Order Arc
On December 9th, following the end of the heat wave and the destruction of the Elements, Useful Spider were mobilized and distributed Spheres to the various shelters across the city, declaring the start of '48 Hours to Restore Order'. Through the manipulations of Kihara Yuiitsu and the Kamisato Faction, they also declared Kamijou Touma and Karasuma Fran as wanted figures linked to the disaster. The Spheres were used by the faction to manipulate the actions of the shelters' residents.

When manipulations led the residents of the Show Business shelter to riot under the belief an ice age was coming, Useful Spider stepped in and started suppressing the rioters, causing considerable harm in the process. Touma attempted to seize the Sphere from Show Business's ruler to stop the riot but was knocked down before he could reach them. The rioters and Useful Spider forces were then incapacitated by an enraged Misaka Mikoto, driven by fury at the looters who had raided Tokiwadai Middle School and School Garden following Yuiitsu's attack.

In the early hours of December 10th, Useful Spider moved into Stage 3 of the '48 Hours to Restore Order' and moved to collect any weapons and dangerous objects, deploying the Breath of Blessing in several areas, including the Academy and Esper shelters, and cutting off access to School District 11's container yard. Later in the morning, they also set up a motor sharing service to aid transport of people and supplies around the city.

In order to access the core of Anti-Art Attachment in the District 11 container yard, Touma, Fran and Toyama Luca planned to set off a delayed explosion at Useful Spider's headquarters in the District 21 observatory to draw their forces back while they accessed the container yard. At the same time, the Kamisato Faction, deeming Useful Spider as an obstacle which was interfering with their search for Touma and risking their chance of saving Kamisato Kakeru, tracked them back to their headquarters and attacked the observatory. Following the revelation of Fran's identity and her confession on the Sphere network, she dropped the Bunny Grey Messenger onto the observatory.

Not long after, Useful Spider found a memo from Touma that told them to help them if they wanted to resolve the situation and decided that it would be the best course of action to help restore the city. Following the loss of the A.A.A.'s core, Useful Spider drew the Kamisato Faction's fire and brought Touma's group aboard one of their helicopters. They helped to get them safely to Heaven Canceller's Hospital so they could use their alternative method to rescue Kamisato Kakeru and break Yuiitsu's hold over the Kamisato Faction.

On December 11th, Useful Spider completed repairs to the city and declared the end of the '48 Hours to Restore Order'.