The Word and the Void, by Terry Brooks

The Word and the Void is a trilogy consisting of the books Running with the Demon, a Knight of the Word and Angel Fire East.

John Ross has been recruited by the Word to help prevent events that can alter the balance of good and evil.  Every night John Ross dreams of the dark place the world will become if he doesn't do something to prevent it.  In running with Demons, his mission is to keep Nest Freemark, a young girl with magical abilities, from becoming a agent of the Void.  Nest has always known about her magical abilities, but she underestimates the amount of power she has and is totally ignorant of her demon heritage.

In the next book it is actually Nest Freemark that helps John Ross from being deceived into becoming an agent of the Void.  A bad experience has caused him to abandon his work for the word, but Nest manages to lead him back to his work as an agent for good.

Finally in the last book Nest and John work together to help a powerful piece of magic to reach it's potential in becoming a powerful force for good.

I enjoyed each of these books individually and as a series.  I thought they had an interesting take on magic in our modern world.  It also has some insightful ideas on how ignorant people are lead to do such dark things.  The series was pretty dark and I don't know that I'd recommend it as a good read if you are feeling down, but when a sunny day comes along it has a great story and take on the battle of good and evil.

I can honestly say that I read these books solely for the purpose of seeing how Terry links this series with the Shannarah series.  Look for a review soon on that new series including Armageddon's Children and The Elves of Cintra.