The Key of All Things

In Torquemada's Spain, scholar and manuscript-hunter Richard Longmoor knows that everything is not always as it seems. His companions, though skilled in war, have no knowledge of the mysteries of the mind. None of them can read a single word. How can he convey to them the magnitude of what he has just read in a forbidden book? How can he convince them that magic is real? This kind of knowledge is worth more than gold. This kind of knowledge is worth a man's life. But which man's?