Kalkin, a successful software engineer leading a seemingly ordinary life, finds himself yearning for something more. Despite his achievements, he feels an inexplicable void within him. To fill this emptiness, he turns to fantasy novels, finding solace and temporary escape within their pages. Among these stories, he discovers "The Octagon: The Academy of Supernaturals," a novel that captivates him like no other. "The Octagon" sweeps Kalkin away with its enchanting tale, weaving a world of supernatural beings and a prestigious academy where they train. The story resonates deeply with Kalkin, providing the fulfillment he had been missing. However, his newfound joy is short-lived when he learns that the novel's author has mysteriously disappeared. As days pass, Kalkin witnesses the novel's rating plummet, and it becomes evident that the story is left unfinished. Countless foreshadowings and unexplored plotlines weigh heavily on Kalkin's mind. Determined not to let the story fade away, he becomes actively involved in managing fan pages and developing theories with fellow enthusiasts. One fateful day, as Kalkin indulges in his dedication to the unfinished novel, a mysterious message appears on his screen. The message, shrouded in a codename, said "You are the only one worthy to know the end, are you interested?" Initially, thinking it is a hoax or prank, but due to his desire to know the complete story itself, the code name made sense to him and overwhelmed with excitement, Kalkin responds affirmatively, expressing his desire to discover the ending. Hours pass, and Kalkin grows restless, awaiting a response that never arrives. Exhausted, he eventually succumbs to sleep. Little does he know that his slumber will transport him into the very world of "The Octagon." Upon awakening, Kalkin finds himself bewildered, a mere extra within the novel's universe. He thought: just who is this guy? as he looked at the mirror. As he grapples with the reality of his situation, he realizes that his journey has only just begun. With an unwavering determination to uncover the missing conclusion, Kalkin embarks on an adventure that intertwines his own fate with that of the characters he had come to love. In this newfound existence, Kalkin faces trials and tribulations, forming unlikely alliances and battling formidable adversaries. As he progresses through the fantastical world of "The Octagon," he learns more about himself and the forces that govern both the fictional realm and his own life. "An Extra's Guide to Survive in the fantasy world" is a thrilling tale of self-discovery, resilience, and the power of storytelling. As Kalkin navigates this extraordinary adventure, he seeks not only to unravel the secrets of the novel but also to find the missing piece that completes his own life.