Salley Vickers, Author . Farrar, Straus & Giroux $23 (320p) IS

The classic threesome—husband, wife, mistress—proves mathematically unstable in Vickers's profound comic novel (following her debut, Miss Garnet's Angel). When 62-year-old Londoner Peter Hansome dies in a car crash, his widow, Bridget, and his mistress, Frances, develop an awkward intimacy cemented by their shared loss. But before Bridget can come to terms with Peter's absence, a "breathtaking" young Iranian man named Zahin arrives to see Peter and winds up moving in as houseguest/housekeeper. Zahin is charming—deferential and superhumanly industrious, he fills the air with the "satisfying scent of lavender Pledge"—but there's also something unsettling about his presence, which drives Bridget to her Shropshire cottage, where she meets Stanley Godwit, a Shakespeare-loving chimney sweep. Frances, too, finds unexpected joy as she learns to make sense of life without Peter. But Peter is never actually gone, as his ghost watches over his former "consorts." This ghost is no jealous meddler; he's more ambiguous, prompting Bridget to meditate on the ambiguity of the ghost in Hamlet and on her own uneasy Catholicism. Though Vickers begins unpromisingly by adopting a pedantic tone, she abandons this posture soon enough, allowing her appealing characters to bloom as the world opens up to them in surprising but logical ways. Philosophical concerns are woven seamlessly with earthly incident, so that bad cocktail parties resonate and good bubble baths matter. In the tradition of the late Iris Murdoch, this extraordinary book will inspire and delight. 6-city author tour. (Apr.)

Forecast: Miss Garnet's Angel touched a chord with its perceptive take on middle-aged self-discovery. Vickers's latest, with its lovely Botticelli jacket, should amply satisfy fans and more firmly establish Vickers in this country.