She walks her back into her parent’s house, she ran her hand over Bellatrix face, and her hazel eyes looked at her cautiously. Hermione's decision to imprison Bellatrix in her parents" old home and train her as a sex slave was driven by her desire for revenge. She wanted to assert her dominance over the former Death Eater and ensure that Bellatrix would be obedient to her every command. With each passing day, Hermione worked diligently to mold Bellatrix into the perfect submissive pet.