Her first instinct was to tell him no. Absolutely not. He was the reason for the scar on her arm. He was the culprit behind years of bullying. The source of so much taunting and teasing. The reason Death Eaters came into the castle that horrible night. The face she saw as she lay on his floor begging for mercy. But he was also the one to throw Harry a wand. To switch sides. To make the right choice against everything he knew. 