David Hardenbrook is the author of The Unknown Witches of Oz (2000). A native of Los Angeles and a computer expert, he used to monitor a Yahoo e-group for Oz fans called Nonestica. Hardenbrook's first book is projected as the opening volume in a planned trilogy, Dan in Oz. The second volume, Jellia Jamb, Maid of Oz, was published in 2008; the third is prospectively titled That Ozzy Feeling.