It was a curse of their blood, she wrote, cells that turned on themselves and the new life that they made. The blood of the purest sire could counteract it if the woman regularly drank from them. Lucius had been sullen at the news, arguing that he was part of the sacred families. And he was, Hermione, admitted, before divulging that she'd studied his family tree and found that one of his forefathers had lain with a muggle-born woman. 