Highfalutin foolishness: a lushly written, leaden-paced historical romance about Nostradamus (Michel de Nostre-Dame, 1503-66) that paradoxically threatens both to sink beneath factual weight (references to 16th-century French dynastic politics) and to soar into the thin air of implausible fictions. Greene's Nostradamus, you see, is an Epicurean magus with 20-20 vision of the future (thanks to astrology). And her house of Lorraine (and the Guise family in particular) is part of a vast underground network--the ""Vine""--of worshippers of the Great Mother, a network which stretches back through time to include not merely the Knights Templar, the Cathars, and the Cistercians, but also the tribe of Benjamin (which somehow migrated to France, via Arcadia, with the subversive cult in their baggage). Furthermore, this is all bound up (obscurely) with the Wandering Jew, the Holy Grail, and King Dagobert II. Still, if the fanciful, arcane convolutions here are dullish and dubious, Greene does a bit better with the complex and bloody semi-historical maneuverings of people like Charles de Guise and Catherine de' Medici--who connives in the deaths of, among others, her husband Henri II, and her sons, FranÃ‡ois II and Charles IX. Nostradamus foresees all these horrors with impotent clairvoyance, and, in dying, he prophesies the coming of a mysterious Prince who will preside over the reflorescence of the Vine. But his undramatic first-person narration fails to hold this history/fantasy/speculation hodgepodge together; and, despite some vivid and knowledgeable use of detail, Greene has expended much effort and much rhapsodic prose on a hybrid that will appeal only to Nostradamus specialists and French-history buffs.