In which Regulus is the father of Hermione. Disclaimer - I don't own Harry Potter. Note - This is a part of my series of stories where Regulus Black lives, but also my Granger Yet series where he's the father of Hermione Granger which can actually involve him not living. The story can be read either as Olivia Granger being Mrs Granger, or the sister-in-law of Mrs Granger. If it is Olivia's brother who raises Hermione, it would be the middle brother Hamlet. Originally though it was going to be her grandparents, but this worked better. As for where the idea came from, it came from the fact I came to the realization that while the HP wiki lists Regulus as having died at eighteen, this depends on both when he died and when his birthday is. As for when, Kreacher tells Harry that Regulus joined at sixteen, but that his death also happened a year later. Out of curiosity I did the math and discovered that Regulus could actually be Hermione's biological father.