Resurrection Is An Ongoing Project of Mine

Regulus Black escapes from the war (more or less) by faking his death and living in exile for six long years. Unfortunately, the death of his mother comes with the end of his anonymity. Offered safety and a job offer by Dumbledore, he finds new purpose as Hogwarts' librarian. But history and secrets are not content to stay in the past, and soon, Regulus will have to confront all it is that he ran away from.

This is of course, inspired by that Professor Regulus Black tumblr post and all the wonderful fics that have already played with that idea!