The world undergoes a cataclysmic change as "Game Dungeons" randomly appear in various places. The monsters emerging from them begin a bloody slaughter of humanity! Qin You, a manhua artist with chuunibyou, has already experienced all kinds of dungeons countless times in his dreams. He knows their levels, combat experience, and dungeon walkthroughs like the back of his hand, and he is convinced that he is the heroic protagonist meant to save the world! And so, his adventure from an all-knowing perspective begins!