First of all, this is the last book in the Jaz Parks series. Jennifer Rardin has died, so no more books from her (sadly).
In this book Jaz struggles with Brude in her head. He is trying to take over, and she has only a short time before she will lose the battle. In order to win she needs to carve his name into the doors to hell. Not the easiest thing to do.
Two new characters turn up in this book. Aaron (at the beginning) and mystery person (don't want to give anything away). Aaron tries to kill Vayl. Jaz manages to stop him, but is hindered from killing him off because he is one of Vayl's long-lost children. They end up helping Aaron in the search for his father's spirit.
As fate would have it, the team ends up together. Dave and Cassandra, Cole and finally Bergman are all essential for the search for Jaz' salvation.
Being the last book, all loose threads are gathered and closure is achieved.