Aberdeen, 1631. University librarian Robert Sim takes receipt of a gift of books recently arrived from overseas, mysterious works on alchemy and hermetics - the pursuit of ancient knowledge. By nightfall he has been brutally murdered. His colleague and good friend Alexander Seaton is left with the task of hunting for clues as to his killer's motive, as well as locating the missing books. What did Sim discover in the package, and what makes these books so dangerous?