The world is vast and diverse, but Wu An's life was bleak and monotonous until he encountered the game app "The Fifth Pillar." This is a story about players controlling characters to explore a mysterious world. It's both a change in the character's fate and a redemption for the player's soul. Besides the familiar mysterious plot, there are many more worlds existing in the background, among passersby, and in imagination, all of which will be revealed in the book. If you find the text-based gameplay tedious, you can skip directly to Chapter 20. This book focuses on the pure mysterious core; all side plots will logically become self-consistent at the appropriate time, so please read with confidence.