Luke's familly (wich didnt live with him) wanted him to get married, so they sended a human girl to his castle, to live with him. Expecting him to turn her into a vampire too, and make her his wife, but he dont want that, so he just avoid any contact with her, or talking about her to his parents. On the other side, the girl that was selled by her father, to Luke's familly was living hopeless and sad everyday.