A brilliant debut packed full of emotion.
The Everneath is a place between our world and Hell, and to go there as a human is the equivalent of signing your own death warrant.
This is what Nikki agrees to do - be fed on for 100 years by an Everliving, in order for the parasite to continue existing. The Everliving are what can be thought of as vampires of the soul, sucking away everything that makes a person individual, leaving behind an empty husk.
Nikki should not have survived the feed, but she does, making her a valuable commodity. She is given six months back on earth to spend with her family, to deal with all the pain and misunderstandings that took her to the Everneath. The 100 years spent in the Everneath is equivalent to 6 months spent on Earth. Soon Nikki has to make an enormous decision, going back to Everneath as a human battery enclosed in its walls or as an Everliving, possibly as Queen.
Revealed in dual time periods, before and after the feed, we are given insight into the reasons why Nikki chooses to agrees to the feed, as well as revelations surrounding the workings of the Everneath, and the history of Nikki's relationships.
The use of Greek mythology, specifically the Orpheus myth, enhanced the plot; Everneath itself brought forth images of Dark Fairy courts, ruled over by a tyrannical queen whose thirst for power is only equal to her thirst for human emotions.