Let me start by saying I really enjoyed this book. That said, this is not my favorite genre. Having read Nicole's work before and loving her writing made me decide to want to read this book.Lela, a woman in her early 30s, is for lack of a better word - complex. I'm sure there are many psychological terms that can describe her, and I have a few in mind, but I'll refrain, for fear of spoiling the story. Lela is fighting many internal and external battles, working as a sleep lab tech (or is she?) and for NASA (or is she?). Her mission is to save the next mission to space, by studying the sleep patterns of the astronauts destined for that mission.Zory is a Russian cosmonaut on loan to the US Space program. He meets Lela and immediately finds her fascinating and attractive. What he doesn't know is that associating himself with her might lead to his demise.This is a very interesting psychological thriller. One thing you need to do while reading it is be 100% focused on the book. One missed line might throw you off. Bottom line, Nicole did a good job holding my interest with this story. If you enjoy twists, thinking a lot during a read, thrills and complex, psychological challenging characters - this book is for you!Thank you o NetGalley for the ARC of this book.