Skryim III: The Dawnguard Wars.

Serana.

Serana watched as the girl tremored on the floor in pain. She could hear her whispering names. Lucia? Sinding was her husband, maybe Lucia was their daughter. But after she let out the pain filled scream, she fell unconscious. It was better that she did. When she would wake up, the transformation she will feel would effect her. Serana watched as the girl's face paled, and the war paint that covered her eyes and cheeks faded away, leaving her face naked. Her dark hair lost it's shine. Soon, when she would wake up, her eyes would be yellow. Harkon turned to Vingalmo and Orthjolf. "You can take her to the Shrine of Molag Bal, to the blood fountain. And bring in one of the cattle. She will be thirsty when she wakes up." Serana turned to her father. "Father....is this really necessary? I mean, she saved my life, but she didn't hand me over to the Dawnguard. Do you think this is the best course of action?" Harkon put a hand on his daughter's shoulder. "Serana, did you even catch a scent of her?" 
"Yeah, she smelled like Dawnguard and old dog." Serana said, crossing her arms as Taniiaae was moved from the hall to a separate room. 
"No, my daughter, the traces of her past and who she was with our there, but she....I could smell her blood, and it had dragon's blood in her veins. I've heard about a young girl who went to Sovengarde to take down the dreaded dragon....and who went to Solstheim to confront the great Miraak. I never knew she would be your savior." Harkon smiled.  Serana looked confused. "Dragons? Miraak?" 
Harkon shook his head, "Forgive me, daughter. You have been asleep for so long. I will explain it all later, but what I want to say is, that this girl is powerful, and will make a powerful vampire. Once she awakens."