Narcissa knew Severus had left Hogwarts and was mad at him. She needed him there to protect Draco. Who else was going to do it for her? Not that she didn't trust Draco- she did but she felt a lot more comfortable knowing that Severus was watching him like he had promised to do so. She needed to know why he had left. True he had fulfilled his promise but still he shouldn't have left like that. Who was to watch her son now?
After gaining a response from him via the journals that he would come by the manor she ordered the House Elves to prepare for his arrival before making her way down the to drawing room at the appointed time. Seeing that he was already there she smirked. She was going to get the answers that she wanted. "Severus," she said simply. "I'm glad you could make it."