Apothecary Raffa and his ragtag band of allies prepare to battle the heartless Chancellor's armies, a conflict he fears will cause untold suffering for the animals being forced to fight.

Hoping to return home after a winter in the Sudden Mountains so he can join his parents in the fight against the evil Chancellor, Raffa must use his apothecary skills while enlisting the help of human and animal friends to survive the journey.

In 1665 London, fourteen-year-old Christopher Rowe, apprentice to an apothecary, and his best friend, Tom, try to uncover the truth behind a mysterious cult, following a trail of puzzles, codes, pranks, and danger toward an unearthly secret with the power to tear the world apart.