To Be Always Pure

On the night Voldemort attacked the Potters, an Auror was the first to appear at their home. He takes Harry to St. Mungo's. His healer discovers that he is under a blood adoption potion disguising his parentage. It turns out Harry is the son of Sirius Black and Iphigenia Malfoy. Orion comes up with a plan to protect Harry from any who seek to use him. AU Story of The Black Secret