Kim Ha-Jun is an ordinary man who has only known neglect, betrayal, and failure throughout his life. But when a mysterious Tower appears, connecting the human world with other worlds filled with monsters, magic, and Gods, his life changes forever. Amid the chaos of participants struggling to survive, Ha-Jun does not choose to become a hero. He observes, analyzes, and learns the rules of the game faster than anyone else. As the Gods begin to notice him, Ha-Jun uncovers a secret that should have remained buried-a truth that could shake the very foundations of the Tower itself.