Zelazny's five Amber books, which appeared variously in the 1970s, featured a magical, multiple-reality land of Shadow ruled by nine quarrelsome princes enmeshed in elaborate, soap-operatic, more-or-less continuous plots. This new entry, then, is less a complete book than a bustling stage-setter for another Amber megatome. Merlin, son of Prince Corwin of Amber, is spending some years on Earth in order to broaden his outlook; unfortunately, every April 30th someone tries to kill him. He ignores the incidents until complications occur: a former girlfriend is murdered by dog-creatures out of Shadow; old friend and rival Luke Raynard shows up enquiring about Merlin's top-secret project, ""Ghostwheel,"" a magical computer designed to locate the mysteriously vanished Corwin. So, after various hair-raising incidents, Merlin returns to Amber--where more murderous doings are afoot: King Random orders him to shut down Ghostwheel, but the willful, independent computer itself resists; Luke turns up--but he's really Rinaldo, son of the (supposedly) dead Prince Brand of Amber, avenging his father's death; Merlin is captured and thrown into a dungeon. Inventive, incident-packed, often fascinating stuff, with flashes of wry humor--but there's not even a token resolution here, and it isn't satisfying in itself. Your move.