The Yellow Plague — John Buckley

Where hidden intentions rise like cream to the surface. And all wizards rekindle the oldest of fears for the Yellow wizards. Death seems suddenly to be a good place to hide. While spell after spell redefines the landscape of Pabstrum. As the final fight for it all sends every hand for it's staff. Then the seal breaks and out pours war!
A simple parchment rendered useless, paves the way for the Yellow wizards to unleash their vengeance on the people of Pabstrum. Saycha, Dorama, and Jamce find a beautiful small town to bed down in, but it isn't long before they have to use their magic to keep from being destroyed. And Saycha feels a geyser of magic welling up inside his mortal coil. Unexplained, but completely welcome in spite of it all.