"I found it in the Black family library at Grimmauld," she whispered, so quiet he could barely hear her. "It’s— gods, Draco the book itself felt like a Horcrux. Full of this oily and viscous magic that gave me nightmares for weeks. I didn’t even know if it would work—" Hermione scoffed. "It wasn’t like I could test the bloody thing beforehand. But the creator had detailed notes on the scope of the magic and how to control it, examples of the potential for such an insidious spell scrawled in the margins. How to disappear anyone from political adversaries to the occasional, pesky, too-smart-for-their-own-good Muggle-born." 