I have loved this series since the first book, but I found this to be the absolute best in the series (so far!). If you have not started this series, I highly recommend it to everyone. The world building, characters, plot are all fantastic. I am not going to be able to review the first 3 books in the series here, but please read them first. Do not start the series at book 4, you will miss too much.
The series is set in London. The main character, Genny is Sidhe Fae, but since her mother was Fae and her father was a vampire, she cannot perform magic herself. She can however "crack" magic, hence the name of her company, spellcrackers.com. Whenever magic is performed in the committance of a crime, she is usually called in to help track the criminal.
Most of this book revolves around a kidnapping, and the fact that the fae of London's fertility has been trapped for a number of years in an amulet. Genny is trying to help release the fertility from the amulet, which takes her on a tarot card quest.
What I really loved about this story was that while Genny and the people in her life, have varying magical abilities, and histories which she is slowly learning about, and while misunderstandings sometimes ensue, they are all played out very realistically (albeit magically) and she really stands up for herself, and what she wants out of life. She does not run off half-cocked when those she loves are in danger (which always annoys me in other books, when it is done to drag out a storyline). And she doesn't let misunderstandings simmer to her detriment.
I cannot wait for the next one in the series!