Entering One By One

There were a total of five keys to the Beyond Heaven Secret Zone that were placed in five mundane realms. If one had the key, one would be able to open the entrance to the Beyond Heaven Secret Zone. Otherwise, the entrance would be barred by a mysterious energy. However, once the final key was used, the point of entrance and exit in all the mundane realms would open as well! Now that the Beyond Heaven Secret Zone had opened in all the mundane realms, this meant that Duan Ling Tian's key was the final key.

Duan Ling Tian was, naturally, unaware of all this.

...

In the northern region. In a valley surrounded by ice mountains and white fog.