FICTION : THE MOON PINNANCE by Thomas Williams (Doubleday: $17.95; 352 pp.).

In this compassionate, lyrically written novel, Thomas Williams--recipient of a National Book Award for “The Hair of Harold Roux”--charts the romance of two young people whose rapture is leavened by wariness and inexperience. In June, 1948, provincial Leah, N.H., seems typically placid, but turbulence prevails in the lives of Dory Perkins and Army veteran John Hearne. These friends are astonished when their camaraderie suddenly flares into a “constant, sickish need” for each other that leads to Dory’s sexual initiation. Despite her joy about being courted by John, Dory feels unnerved by her intense longing for him, and he can barely cope with his responsibility toward this malleable, unworldly girl. To help put their relationship in perspective, they part temporarily. John rides his motorcycle to California where he hopes to find his long-lost father; Dory acts as caretaker at a local inn inhabited by European guests, some of them menacing. Before their separation concludes, John and Dory face tragedy, upheaval and the question of how durable their summer passion really is. The pristine beauty and originality of Williams’ prose distinguish this story, as do his insights into the ambivalence that often accompanies youthful infatuation.