Janie and Benjamin have promised to protect an ancient magical book, the Pharmacopeia. It belongs to a mysterious apothecary.
Now they're on the run, the apothecary has disappeared, and Russian spies will stop at nothing to get the book.
Can Janie and Benjamin unlock the secrets of the Pharmacopeia? What strange powers do the apothecary's elixirs hold? And can Janie and Benjamin save him in time to fulfil his impossible plan?
'Inventive, smart and fun, an absolute delight.' Rebecca Stead
