Just my 2 cents: I loved this story up till the librarian showed up. It was a hell of a cliffhanger with derik, and introducing a new character made me groan because I know that it means several chapters minimum before we get back to it. I personally want all the characters introduced within 3 chapters.
That said I love that you flesh out the characters and I love that though derik has a big dick, her focus wasn't at first driven by it... It was a slow process and I thoroughly enjoy that. I also write stories in a similar fashion.
Patiently waiting...