*Prologue*
River Song was not the only child born to Rory and Amy Pond. There was yet another 'Child of the TARDIS', another child born to the Ponds. Their daughter appeared on the TARDIS after they were sent back in time by the Weeping Angels in Manhattan. She was a tiny baby so she went through a few regeneration until she was able to survive.
The Doctor knew he couldn't raise the baby so he went to earth. The little girl was left on the steps of a suburban home in Boise, Idaho. She was adopted by Allan and Hayley Walther and they named her Halyn. Things were perfect until she was six months old.
The night marking six months after her birth, a demon visited her. He cut his hand and stuck he bloody finger into her mouth. Hayley walked in and screamed as the stranger stood over her baby. When Allan got in there it was too late to save Hayley. The room went ablaze and Allan quickly saved the baby girl.
Allan was a hunter of the supernatural, he had heard of this demon but he never thought he would be a victim to him. He was determined to find it and kill it. He took his daughter and they began crossing the country in search of the demon.
They moved from motel to motel Halyn learned everything that had to do with hunting from her father. Once she learned to read she was determined to be brilliant. She didn't want to hunt for a living. She wanted to be a doctor and help people in that way.
When she was seven years old she got caught in the crossfire of a fight her father and a demon got in. She died but that wasn't going to be her ending.
Much to her and her father's shock, a golden light surrounded her and she started changing. She was a different body but the same girl. That freaked Allan out. She was some sort of supernatural being and he wasn't sure what to do with her. She was scared too because he hunted creatures that weren't human.
He could never hurt his daughter so he decided he needed to keep her safe. He dropped her off to live with his sister. Halyn lived with her aunt and her cousin, Will.
Things would seem to be normal for a little while, but things never are what they seem...