Jeon Jungkook returns from Busan and moves back into a shared family-friend's home in Seoul to live with his friends Kim Taehyung and Park Jimin. When Jungkook discovers the families Book of Shadows in the attic, he learns that he and his friends are the most powerful wizards ever known, destined to protect both innocents and the world at large from demons, sirens, and other evil creatures. Jungkook, reasonably suspecting the book to be a novelty, reads its initial inscription—unaware that it also happens to be an incantation activating the friends' supernatural powers once all three are reunited in their ancestral family-friend home.