A mysterious substance scattered across the world, varying in size, shape, and texture, sometimes even changing based on the observer and how it is observed. The only common feature is its color – as black as an abyss. Wherever the Beacons are found, Anomalies follow.
The phenomena brought by the Beacons are akin to miracles and revelations. Ancient humans often regarded the Beacons as sacred objects, embedding them into obelisks, sealing them beneath temples, or casting them into stained glass frames. These acts can be seen as both “offering” and “sealing”.

These entities, which are fundamentally different from the known universe and should not exist, are brought into the world through the guidance of the Beacon.
Due to their incomprehensibility, humans can only explain these Anomalies by relating them to their own experiences, thus giving rise to numerous myths, legends, and strange tales. The appearance and activity of Anomalies have spanned the entirety of history. Sometimes, they are swiftly covered up by secret alliances, leaving only obscure records in historical texts; other times, they cause great disasters and leave unsolved mysteries.
In the technologically advanced modern era, the frequency of anomalies has significantly decreased.

In current understanding, the Babel Library is an endless labyrinth formed through infinite permutations based on the space within the Babel Tower. It endlessly rearranges human-recorded text and knowledge to exhaust all possible combinations of words: past histories, ongoing stories, and future prophecies.
This is an infinite recursion beyond human logic and beyond the capacity of three-dimensional space, resulting in a magnificent anomaly in a dimension surpassing human comprehension.
“The library holds everything; it is the sum of all things our languages can express.”

Eme-an is one of the oldest existing secret alliances, founded by the legendary sage Elish. Elish discovered the first recorded Beacon in human history, known as the Beacon of the Babel Library, in the land later referred to as 「the Land of Roaring Lions」, and built the Babel Tower there. Many scholars, drawn by the Anomaly of the Library, gathered under Elish’s leadership, leading to the birth of Eme-an. The name Eme-an is a modern transliteration of an ancient term meaning ‘the voice of the gods’.

World Calendar is the calendar currently used across various countries. It marks the year of the first artificial satellite launched by Cyril as Year One, commemorating humanity’s first glimpse of the world’s shape, shedding ignorance, and stepping into modern society.
Coincidentally, in the same Year, explorers discovered the last unknown islet in the ocean, marking humanity’s complete understanding of their planet.
Year One of the World Calendar also signifies a pivotal turning point for the secret alliances. With the satellite’s launch, Eme-an, the Babel Tower, and the Babel Library faded from public memory, heralding the start of a new chapter in history.

The rooms in the Babel Library, marked by librarians over the years during their various explorations, are collectively known as the Known Sector.
In contrast, the vast unexplored area is called the Unknown Sector. Compared to the Unknown Sector, the Known Sector is merely a drop in the ocean. The Unknown Sector holds infinite possibilities and is the place every librarian dreams of exploring.

Belonging to the ancient eastern country of Qian, the secret alliance WeiShi is renowned for its pragmatic approach among all secret alliances, with its paramount principle being the safety of Qian’s people.
The history of WeiShi dates back to the early days of Qian civilization. Legend has it that the first emperor once asked scholars about the origins of ghosts and gods. A scholar solemnly replied,
“How can we inquire about the spirits if we haven’t asked about the living?”
The emperor laughed and never mentioned the topic again. Thus, the spirit of WeiShi was established and has been passed down ever since.

In pursuit of truth, many members of Eme-an willingly set out from a room in the Known Sector, venturing into the endless Unknown Sector, never to return until they have explored the entirety of the library. They form teams known as the Never-Returning Teams, embarking on what is known as the Journey of No Return.