The Far Side of Forever

The balance stone - It was the magical focus that kept Laciel's world safe, but now someone had stolen the Stone. And unless the sorceress Laciel and her five companions on this quest could survive the unknown enemy's traps, find their way through the gates between worlds, and recover the Balance Stone from the Far Side of Forever, Laciel's homeland would be destroyed beyond hope of reclaiming. Each of the six adventurers had been chosen by the wizard Graythor for his or her unique skills. As magic wielder, warrior, shape-changer or thief, each would be called upon to play a role no other could fulfill and all must survive to reach their goal or everything would be lost. But someone was determined that they would fail, someone who had mobilized deadly forces against the questers on all of the world-dimensions through which they must pass... (from the back cover of the DAW Books first edition)