Amazon.com (ISBN 0345354915, Mass Market Paperback)

Split Infinity is the first book in Piers Anthony's Apprentice Adept series. Here two worlds exist side by side: Proton and Phaze. Proton is a science fiction world, where everything works in a logical and scientific manner. Phaze is a fantasy world similar to Anthony's Xanth in that there's no such thing as science--it's all done with magic! The wild plot involves a young adventurer named Stiles who lives in Proton and learns that his "double" in Phaze has been murdered. To solve his own demise, Stiles must travel between the two realities, each abounding with the expected confusions and unexpected plot twists for which Anthony is famous. An artful blending of SF and fantasy clichés and situations, Split Infinity shows Piers Anthony at the top of his ingenious game(s). --Stanley Wiater