"I had wondered that myself for a long time. It wasn't until long after the war it was divulged that the Death Eater Rookwood was also an Unspeakable, and that he caused a lot of chaos when he defected. He even killed Bode with that Devil's Snare in St. Mungo's to cover up his trail. When Croaker finally captured him, the truth finally came out. My mother could have averted the wizarding war if she had captured Quirrell in Romania."