A Weapon of Mathematics (Paperback or Softback)

The Sorcerer's Deluge swept the world, destroyed civilization, blew the Moon out of the sky and ushered in the Age of Magic.

It was triggered when a mathematician discovered a new series of numbers. Like negative, irrational and imaginary numbers, "commotic" numbers seem like purely mental constructions but turn out to describe the real world. Unlike the others, expressions written with magical or "commotic" numbers also directly affect the world, by changing the relationships between things and places. Used ignorantly, mathematical magic leveled cities, brought down fire from the skies and killed millions. But a mathematician trained in magic can bring needed rain, heal wounds, travel instantly between places and use spells to do a hundred other useful things. For eight hundred years, society has been painfully rebuilding, aided by magicians of mathematics.

There are two new, lunatic cults gaining power in the Kingdom, each crazier than the other. They worship the "Unborn Gods," one repressed and puritanical, the others Dionysian and drunk. They threaten the Kingdom, and more importantly, they threaten the very concept of rationality. Hondoll, the King's Magician, is charged with standing against them. He has a few allies and many enemies.

Will reason and courage be stronger than craziness?