Last summer, when Hermione perfected her refined Polyjuice potion recipe - the one that focused on transmogrifying one specific appendage in a very specific way - she knew she was onto something big. But she couldn't quite bring herself to share the discovery with the wizarding world. The potential for misuse in the wrong hands - any hands but hers - was astronomically high. So she kept it to herself for the better part of a semester, conducting as much "solo research" as possible. But the day came when she decided she needed another test subject to conduct full and proper field tests. So she invited Ginny over for tea, and shared the results of her work. She chose Ginny because she trusted her... the fact that Ginny gave fantastic blowjobs had nothing to do with it!