Great start into the day when I saw this updated, reread some chapters and reaffirmed to myself this has one of my favorite OC's in fanfiction. Normally filtering them out via scryer for example is the first thing I do. Spoiler Golden moment for example how he couldn't believe who Harry really was, since nobody would ever stash anything important with muggles! And this is the first time I see where Dumbledores genius with putting Harry to the Dursleys shines a little through. Petri seems honestly confused, Albus played him without really trying to. Also suddenly there is some kind of backstory hinted for Rosenkol, apparently he didn't take Petri seriously when they first met either and surely Petri didn't go out of his way to teach a house-elf magic.