I believe this is a spinoff of the Knights of the Black Swan Series which I have read most of if not all.
Atalanta Ravin was left standing at the altar and decided to take a good look at her life. She decided to just pick up and leave her life behind and go live on a boat in the Boston Harbor even though she knew nothing about boats.
She takes her boat out for a cruise one day and finds herself surrounded by a strange fog. When she returns to harbor that afternoon, she discovers she is in an alternate universe.
This is where the book joins with the Order of the Black Swan. There are some of the old cast and some new characters.
This book was just okay to me. It wasn’t horrible but it just did not grab my interest enough to continue to read the series.