There is such a book in Wuyou Continent, which can detect some secret messages in some people's hearts and then record them.
It can contain secret recipes for elixirs, chapters on exercises, and of course it can also be some people's little secrets.
And because there are only some intermittent articles in it, it is a fragment, but a certain being is not satisfied with this, because it is like reading some novels that dig holes without filling them, so he targeted a few people and planned to make a complete story.