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.

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.

Raffa Santana is a healer, not a fighter. As a gifted apothecary, he has amazing instincts for unleashing the potential of magical-seeming plants. But his skills have failed to free the animals that the heartless Chancellor captured and turned against the people of Obsidia directly threatening Raffa's friends and family.