By the author of several smoke-and-mirror novels of metaphysical speculation (City of Gates, 1993, etc.) in which Time, human history, and the mystic binges of saints and outsize sinners collide, mix, and swirl off in further mystery. Here, a Roman general -- with all the trappings of ancient Rome but savvy as to electricity, radio, and air support -- is marooned with his garrison in a desert outpost and there confronts the edge of eternity. Octavius has his orders from the decaying empire's center at Tivoli: Hold the garrison against the Savages, or Blue Warriors, a foe never seen. Octavius is a careful commander who maintains polite relationships with the neighboring Bedouins, whose spare lives answer the demands of the desert and its vast uncertainties, while within the severe, evanescent world of the camp, human dramas play out: Captive women are brought in, with their children, as ""whores""; there are deserters and executions; and dissension racks the family of a dead Arab chief. During the seven years of his service, Octavius communicates with his beloved wife Livia -- in letters, then a journal, then in his increasingly fevered mind. He walks through the tombs of dead leaders, hears their voices and the voices of his old tutors, one declaring that all questions have answers, the other that Octavius will be able to ""be alone with difficult questions."" At last, shocked into a terrible wrong and prodded by difficult cosmic questions, Octavius treks into the desert, only to find a horror -- indicating he's gone too far, asked too much. Again from Elliott come symbols barnacled with religious and philosophical reference: primal fish (like the ""sacred carp"" of City of Gates), for example, or women as whores/seeresses/earth-mothers. Octavius's epiphany is a shade sensational, but Elliott skillfully sustains an eerie cosmic unease in a setting where men and their maps are but figures in the sand.