THE LAST TO GO <i> by Rand Richard Cooper (Avon: $7.95) </i>

Rand Cooper uses a series of overlapping vignettes to present a sort of Cubist portrait of a disintegrating upper-middle class marriage. Dan and Mary Ellen Slattery seemed like an ideal couple: Their divorce shocked everyone who knew them. Cooper scrapes off their sleek veneer and examines the gradual erosion of love that transformed devoted partners into strangers and, ultimately, enemies. The story is divided among several narrators, but these characters sound too much alike for the switches to be very effective. Toby, the Slattery’s son, who watches his parents separate (and never forgives his father for leaving), is the most credible observer; the version of the separation recounted by a heretofore unmentioned neighbor near the end of the book reads like an early draft of a different story.