Sex, old age, and death haunt these chilly tales by eccentric virtuoso Barnes. An octogenarian husband is caught in an affair with an elderly widow and abruptly leaves his wife of many decades. A woman finds she can communicate with her demented and increasingly filthy-minded husband only by reading to him from cookbooks. And in the book's most harrowing tale -- a tiny masterpiece called ''Hygiene'' -- a senior citizen rides the train to London, happily anticipating his annual tryst with a longtime mistress. ''Were you as young as you felt, or as old as you looked?'' he blithely wonders. By the train ride back he has his chilling answer.