Under the Banner of Heaven (2022)

A young maid Duk Im is ordered to visit the late Royal Noble Consort Yeong’s funeral. There she meets the Crown Prince who also secretly came to say goodbye to his grandmother. Duk Im learns about the forbidden book which King Yeongjo despises because of a certain phrase, and is warned that she’ll be losing her head if she is to read it. One day, she hears that the book is kept in the Crown Prince’s library, which makes her worried.