The Girl in Blue

Sam and Dean keep running into a mysterious woman. She claims to be a hunter, but although she knows all about the creatures Sam and Dean hunt, she doesn't quite fit the profile. When she begins to show knowledge of things that even Bobby can't find the lore on, the boys have to figure out who this girl is and where she came from. Perhaps this lonely traveler is lonelier than they realized.

I haven't decided yet, but there will be an eventual XReader. I'm leaning towards Dean, but we'll see how it goes.

(This is a Doctor Who and Supernatural cross over. It doesn't follow along to any particular episodes, but it does give spoilers and references some episodes. However, if a chapter contains spoilers, I'll put a warning in bold at the beginning of the chapter.)