Here’s another answer in response to a recent set of book group questions (warning: SPOILERS!):

Q.    Can you explain the curse that Dale suffers under after killing the Persian craftsmen at the beginning of the book?  There was some confusion among our group as to what exactly that curse entailed – apart from causing his fellow soldiers to slaughter innocent townspeople – and how it affected Dale later (I think we began to confuse it with the Morton’s cursed left hand legacy).

A. Yeah, I could have done a better job of distinguishing these two forces working on Dale’s psyche. First point: the craft that the sorcerer used on the soldiers was distinct from the curse–he used their killings to power the more difficult craft that neutralized Dale. The curse (I realized this on later reflection) therefore involved Left-Hand craft–using the life force of others to power a spell–which makes it a bit hypocritical, or at least (in the sorcerer’s view) fighting fire with fire.

The sorcerer’s curse tormented Dale whenever he planned further combat, though it turned out to have a particular focus on protecting the Islamic world, so with the help of the House (and, less consciously, Scherie), Dale was able to get over it enough and in time to kill M before the party.

Perhaps Dale could have better resisted the curse earlier and yet preserved his sanity if he weren’t already subject to a continual temptation to the opposite course of action: the Left-Hand voice deep in his psyche. That presence meant that, if he totally broke through the curse’s restraint on combat, Dale feared he might never stop killing.

So, during the first part of the book, the two contrary impulses grind Dale’s mind between them. His resulting mental situation is a very loose and fantastical analogy to the all-too-real PTSD faced by many veterans (the analogy doesn’t bear up to too exact a comparison). Dale is “spell-shocked.” His freeze-up during his first attempt to go after Sphinx is in part a result of this.

Though diminished, the curse and the Left-Hand voices still remain a problem.