While the non-linear nature of the timeline at some points had me a bit confused I loved the details included, like the music box, like the very believable descent into magic that we see in Bellatrix, as well as the juvenile decor of the sisters' childhood room (chocolate frog poster, really?) juxtaposed with the adult world into which they're suddenly cast. It works so well!
Severus Snape and the Marauders: