In 2024, a coastal city. Underneath an old apartment building built during the Republic of China, there is a strange 18-story building - the "Abyss Strange Building". This building overlaps with the real world, and every once in a while, a group of people will be randomly "selected" to enter it.
Entry conditions: There are no rules to follow. It could be taking an elevator at midnight, walking into a basement, or just opening the wrong door. Once inside, you must complete the "rules" of each level before you can return to the real world.
Price of return: Those who complete all 18 levels can return to reality. But - at some inadvertent moment, they will be pulled into the mysterious building again and start a new round of survival. No one can escape completely.
