When this book is good, its outstanding. The highlights:
- the Underground Railroad setting
- the very real, physical danger that ups the stakes
- the tension between Hester and Galen, especially at the beginning
- the history of slavecatchers and patrols

However the pacing of this was all over the place, at times rushed and at other times dragging, and the sheer volume of characters (I think mostly from other series) contributed to my feeling like I couldn't quite get into this.