From one day onwards, mysterious entrances called "rifts" began to appear all over the world. These fissures come in various shapes, and may be a distorted curtain of light, an inconspicuous cave entrance, or even an old wooden door that suddenly appears in the wall. They appear and disappear randomly, sucking some people nearby into them.
Those who are sucked in will enter a vast alien world called the "Secret Realm". The secret realm is not a tower, but a boundless special space with different ecological environments. It is said to be composed of countless broken land masses, forests, lakes, underground caves, etc. The deeper you explore, the more peculiar the environment becomes, the more precious the resources are, but also the more dangerous it becomes.
The secret realm is filled with strange animals, plants and mineral resources that are not found in the outside world, and there are also many "spiritual beasts" that are intelligent and can communicate with people. They formed tribes or kingdoms. Similarly, there are also spirit beast merchants called "wanderers" who wander around the secret realm, exchanging special products from the secret realm with humans for creations from the outside world.
Humans who enter the secret realm are called "explorers", and their goal is usually to find rare resources to bring back to the real world, or to try to find the core secrets of the secret realm. But the secret realm is vast and full of dangers, and no one knows its full picture.
The protagonist Liu Ning accidentally fell into a stable crack leading to a secret realm after accidentally missing the stairs, and came to a safe but closed initial area - a cave with water and glowing moss.
