The Lion and the Unicorn

In darkest days of the war, the Order uncovers a new forbidden item being sold in Knockturn Alley: human beings. Lupin poses as a buyer to save some of the girls, muggle and mudbloods, but has he made the wisest or worst decision when the girl he chooses has no memory? What has he gotten himself into? Creepy nursery rhymes abound (see title). Please R&R!