There is a first book in this series, Unborn, that you will want to read before this book as it is the start of Khara's mystery into who she is as well as builds the relationships that she has in the second book.
Welcome to the underworld, where Hades rules and Khara feels more at home than she does during her time above. Khara has returned to the land of the dead to seek answers as to what she is and who her mother is as well. The underworld is a place of secrets and it takes more than a few questions to pry the truth from those who reside there living or dead. Khara journey started out just for her but her outcome is going to affect everything above and below.
I really really dislike it when I am unable to finish a book and I really do try to finish reading every book that I start reading even when I want to throw it against the wall in frustration. However, there are times when I just cannot do it and unfortunately Unseen has fallen on to my DNF shelf. I made it more than halfway though the book, I think I only have maybe 80 pages left but I kept thinking that I could be spending my time reading something I enjoy.
The first book in this series was not my favorite but the book ended with a cliffhanger that had me wanting to come back, plus I knew this book was going to be set in the underworld which were the parts I enjoyed in the first book so I thought that Natusch would build upon this positive of the first book. However Natusch never really built the underworld, I never got a sense of what the underworld looked liked according to Natusch or even how it felt there other than Khara feeling at home.
This book had a lot less action/fighting in this book and I felt like the book/plot just went in circles as I was reading it. The plot was mainly executed by Khara running around the underworld looking for answers, never really finding them, then people telling her she should be looking for answers and then she starts out again to search for answers and then people telling her should be looking for answers and then she starts out again to search for answers (I am well aware that I repeated myself there, just trying to make my point).
Natusch has some interesting ideas and I think if the premise was executed in a different way this book would be a winner, but the lack of anything happening in this book and lack of world building (I mean there are so many options and ideas that you could have to create a vivid image of the underworld) that I just could not finish this book and will not continue on in this series.