The Sinsar Dubh is an object of power in the Fever Series. It's an ancient book of dark magic that contains the power of absolute control over both the worlds of Human and immortal Fae. Whoever gets it first rules all. Of the players hunting it, MacKayla Lane is the only one that can sense and track it, and everyone is trying to control her.
The Sinsar Dubh is one of the Unseelie Hallows, which include:
- Silvers (mirrors through which they travel)
- Book (Sinsar Dubh)