An engaging autobiographical novel, really as much memoir as fiction, from the mandarin stylist renowned for both personal history (A Stroke of Genius, 1995, etc.) and zestfully inventive fiction (Terrestrials, 1997, etc.). West’s subject this time is his wife, poet and naturalist Diane Ackerman (herself a noted nonfiction writer); specifically, their romantic friendship throughout the 1970s when both taught at fictional “Coriolus” (surely Cornell) University, and formed a bond uniting their separate, then increasingly common explorations of the worlds of art and science. He waxes rhapsodic when devising the affectionate names “Swan” (for both her physical grace and her love of flight) and “Ariada Mencken” (a clever anagram for “Diane Ackerman”); impishly comparing them both to Dante’s Paolo and Francesca; and celebrating each’s penchant for (wonderfully awful) word coinages and puns—to wit: “Our oral lives (in the verbal domain, that is) have always been two interacting Niagaras, opaque and weird to overhearers.” Chronology is treated cavalierly, as West noodles agreeably on such topics as their fascination with astronomy (“Far from star-crossed, we were cosmic lovers”), his own admittedly eccentric writing habits and passion for foreign novels and Milton’s poetry, hers for close observation of the physical world and sedulous “conveyance” of what she learns to others. A book within a book in effect develops from accounts of their travels to (then) Cape Canaveral to observe Viking and Voyager liftoffs, shepherded by their pseudonymous colleague Raoul Bunsen (“an astronomical combination of Andre Breton and Salvador Dali”), who, we’re probably safe to guess, is a fictionalized Carl Sagan. The book tools along aimlessly, but never fails to entertain, while creating a rich illusion of intimacy with two gifted and fascinating people for whom curiosity is one of the highest human virtues. It’s probably something less than an authoritative dual biography. On the other hand, what a terrific Valentine’s Day present—for Diane Ackerman, and us.