Kush, an imagined sub-Saharan country in Africa, a poor peanut-producing territory once ruled by the French under the name of Noire, is the improbable setting for John Updike's uncharacteristic new novel, "The Coup" …, and he has taken immense pains to make the territory tangible in some dazzling passages of physical description and recreation. "The Coup" is really more fable than novel. At first reading, it seems to be a number of books in one, and veers abruptly from the lyrical to the intensely declarative to the hilarious, from character to caricature; but it has a high moral point of view, and some exotic set pieces, which contrive to move it toward the fabulous. Updike has become the most Nabokovian of writers—who else takes the trouble to make such beautifully modulated sentences, or gives prose in general the carefully observed attention more commonly given to poetry? "The Coup...