A masterpiece! The manhwa is so well-made. One of the best manhwas to read.
The plot and progression is stable and balanced. The MC is teleported to another world (yes this is an isekai lol)
The basic part is he is a bookstore owner in another world. He wants to see the books he owns, when he let people borrow the books (It looks like a normal book to him) but to other people it is either Horrifying, Bizarre, Magical, Divine or just Unknown in general.
The MC gets misunderstood every time, thinking that he is omnipotent and can see the future. But he just uses Psychological Attacks and using Cold Reading, basically a con-artist.