I haven't read The Calling series so I wasn't familiar with the characters or premise of this spin-off series. I have to say that I enjoyed this book more as I read the books that followed it. It is in this book that we meet the secondary characters that will take over the series Diana Reyes and Jesus Hernandez. This book stands alone as we meet Nemesis, Goddess of Vengeance and Justice on earth as FBI Special Agent Helene Alexander. She and her new partner, SA Miguel Sanchez have to find and apprehend the serial killer known as "The Butcher". Can a human teach a Goddess that Justice and Vengeance aren't always the same thing and the ends don't always justify the means. I don't know but he can and does teach her a few things about love. This is a super, sexy paranormal romantic suspense novel.