Mme. Yourcenar's Memoirs of Hadrian (1951) is, for a scattered audience, a surreptitious touchstone: finding that a new friend has read it is like receiving an unexpected gift. The Abyss is a more awkward and problematical book whose greatest excitements work against some of its qualities as a novel. The stage is the Counter-Reformation and late Renaissance, and the protagonist is Zeno, a bastard-born alchemist, healer, and questioner who has roamed Europe among Catholic, Lutheran, Jew, Moslem; Spaniard, Italian, Lapp. The first third of the book introduces an untidy, sometimes wearying, plethora of characters and events: the rising mercantile fortunes of Zeno's canny Flemish uncle; the fates of his stepfather and mother at the siege of Anabaptist Munster; the brief, intense Calvinist conversion of his half-sister; the soldier-poet fortunes of a younger cousin. By contrast the central portion of the book--Zeno's pseudonymous return to a monastery in his native Bruges during the Spanish occupation--is as magnificent as anything in the earlier book: a middle-aged thinker's silent odyssey through suddenly revealed uncertainties of memory, perception, and induction where the mere act of thinking becomes an image of the alchemist's opus magnum--the transmutation of metals. Strangely, this inner journey makes the denouÃ‰ment--Zeno's arrest and trial for heresy--something of an intellectual and emotional anticlimax. Despite the crowded canvas this is not a novel of action or character; indeed, the judicious austerity of the characterizations verges at times on mere perfunctoriness. In Memoirs of Hadrian, the wonderfully finished first-person narration transfigures analogous qualifies into a gravely mirroring simplicity. This highly episodic third-person narration is a less satisfying novel but if anything a deeper imaginative challenge: an attempt to dissect the dark process of unmaking and remaking which constantly recasts experience in not only the alchemist's but the mind's alembic.