Prompt: Grindelwald is captured, they track down Graves, but instead of finding a locked up and tortured Graves they find Graves naked and in a collar, napping on a soft bed without a hint of recognition in his eyes when they awaken him. Turns out Grindelwald messed with Graves's mind, removed all his memories and made him believe that he's Grindelwald's pet, utterly devoted to him and his cock, without any cure due to his extensive talent. Grindelwald is smug and Graves gets all whimpery and pleading when he realizes they aren't taking him to his Master and no one knows what to do. Bonus if Graves no longer knows how to handle himself like a proper human, eating out of hands or a bowl, sleeping curled up at the foot of the bed, responding to 'pet' or similar rather than his own name, etc. Praise and toys and the like would be appreciated.

Chapter 4:
http://archiveofourown.org/works/9306503/chapters/21460064