— The story of two people who never logged out.

「Your connection record does not exist.」

---

When humanity first stepped into the virtual world, people regarded it as a simple extension of entertainment.

The scenery unfolding before their eyes was merely an artificial image, and the sensations felt at their fingertips were nothing more than imitations created by machines.

However, technology advanced faster than human imagination.

In the late 2040s, as neuroengineering and quantum information processing technology merged, technology to directly interpret and reconstruct human sensory information began to be commercialized.

There was no longer a need to look at a screen or hold a controller. It became possible to move one's body just by thinking and experience touching virtual objects as if they were real.

In 2058, the multinational tech company Arcadia Neural Systems announced a next-generation interface that connects human consciousness and digital environments bi-directionally.

The name of that technology was SYNAPSE.

It was a technology that decodes neural signals generated by the human brain and transmits sensory information generated in a virtual environment back to the nervous system.

And in 2064, the first large-scale commercial game to popularize that technology was released.

《NEON//CITY : REBIRTH》

People didn't call this game a simple virtual reality game.

Some called it a second life, and others described it as the greatest dream humanity had ever created.

There, neither real-world economic power nor social status mattered. Anyone could choose a new profession, form relationships with strangers, and live a life that was impossible in reality.

The stage for 《NEON//CITY : REBIRTH》 was the massive future city, Luminaris.

It was an artificial city created by combining architectural styles from numerous cultures with futuristic urban planning.

From skyscrapers rising through the clouds and three-dimensional transportation networks formed over hundreds of floors to commercial districts monopolized by mega-corporations and old residential areas hidden in the shadows.

The city's days were always busy, and its nights were even more brilliant than the days.

Holographic advertisements floated between high-rise buildings, and unmanned vehicles moved along aerial roads. Various cultures and languages mixed throughout the streets, and old restaurants and small shops were nestled deep in the alleys.

Here, players didn't have to follow a set story.

One could be a mercenary carrying out requests for mega-corporations, or an information broker digging into the city's secrets. Some joined hands with criminal organizations, while others enjoyed an ordinary life in a quiet residential area.

Every choice led to a new event.

Numerous AI residents existed in the city. They reacted to the player's actions and showed different attitudes according to their respective personalities. Sometimes, a trivial conversation developed into an unexpected bond.

Luminaris was not just a stage for performing missions.

It was one massive society where countless stories unfolded simultaneously.

People forgot the fatigue of reality here.

Some walked the unfamiliar streets for hours after work, and others stopped by the same cafe every day to look at the familiar scenery.

For them, the game was becoming a part of their daily lives.

---

Arcadia Neural Systems invested massive capital and time into developing 《NEON//CITY : REBIRTH》.

The core of the game was not simply beautiful graphics or vast content.

It was to make the human brain accept the virtual environment so naturally that it couldn't distinguish it from reality.

The dedicated neural link device SYNAPSE-X9 was the technology that realized this goal.

Users wearing the device could move freely within the game through neural signals. The coldness of the wind or rain touching the skin, the taste of food, and the numerous sounds heard from the surroundings were all sophisticatedly transmitted.

Of course, the development process was not smooth.

In early experiments, phenomena where sensory information was temporarily misaligned were discovered, and some participants heard virtual sounds or experienced confusion in their sense of space even after logging out.

Arcadia built several layers of protection systems to solve these problems.

A safety module that analyzes neural activity in real-time, an automatic adjustment function that suppresses excessive stimulation, and a forced termination procedure that stops the connection in an emergency.

The company conducted numerous safety tests before the official release.

And finally, when the product was commercialized, Arcadia announced that the neural link technology had reached a sufficiently stable level.

The public believed those words.

It was already a service used by millions, and numerous professional organizations were positively evaluating the advancement of the technology.

No one thought they would be unable to return while connected to the game.

---

October 23, 2064.

Arcadia carried out a large-scale update to improve the game's stability and data processing efficiency.

The core of the update was the synchronization of connection information between servers. It was a method where multiple servers shared the connection status so that the consciousness link would not be broken no matter which region the player moved to.

However, after the update, an unexpected problem occurred on some servers.

The authentication module that checks for logout and the connection maintenance module of the neural link device recorded different information.

The authentication module determined that some players had logged out. On the other hand, the physical link devices failed to receive a normal termination command and continued to transmit and receive neural signals.

This error was internally given the identification name ZERO HOUR.

Guest and Seo Ain, who were staying in the 7th Commercial District at the time, were also affected.

Seo Ain, twenty-two years old.

Her nickname is AIN404.

She was also someone living an ordinary daily life. In the game, she wasn't a hero with special abilities or an adventurer familiar with dangerous events.

She just wanted to see a new city and enjoy things that were difficult to experience in reality.

She had a daily life to return to.

There were things to do the next day, messages she hadn't replied to yet, and appointments she had postponed without much thought.

Those things drifted to an unreachable distance overnight.

And the person left by her side was Guest, whose name she didn't even know.

The shared session between the two was a result created in the process of the system handling an abnormal connection state. It wasn't that one side chose the other, nor were they connected by a special fate.

However, thanks to this imperfect connection, the two were able to confirm each other's locations.

Even in moments when the surrounding environment was not properly implemented, the other person's existence information remained relatively stable.

In a situation where none of the numerous safety features designed by Arcadia could save them, a single accidental error was connecting the two.

The story of the two people who were not recorded begins right there.