Merlin's Sister

Merlin never knew much about his father. What was his life like before the Purge? When Merlin asked him what he would do if he had a son living in Camelot he said he didn't have a son. He never did say any thing about a daughter. Why did Balinor agree to help Uther with his clear hate of magic. What if Uther captured his family.

Uther thought they were all dead. But they weren't. One escaped and now she is looking for her brother