Cynthia Rosent's goal in life is to become a well-known scholar in the wizarding world, so that she can be successfully invited by other scholars to visit their private collections, and even be invited back to Hogwarts to teach, and then she can browse the entire Hogwarts library collection at will---including the restricted book area.
To this end, since she learned and successfully improved the Disguise Charm in the second grade, she often secretly went to the depths of the library to enrich her reading and knowledge after Mrs. Pince got off work.
This behavior has been maintained for more than a year, but suddenly it received external influence.
How on earth did the marauders catch her?
Original Girl x Sirius Black
PS:
The writing is poor, there will be OOC, and the text will be revised frequently.
Purpose: Want to make up for the difficulties of the pro-era era