The author of three previous novels returns with a disappointingly sedate summer romance set in a bookstore. Once again, Schine's story hinges on a piece of writing that changes a woman's life. In Rameau's Niece (1993), an 18th-century manuscript was the obsession; this time it's a love letter that arrives at Helen MacFarquhar's small, highbrow bookshop. Mysteriously addressed to ``Goat'' from ``Ram,'' the letter--and its overheated prose--spreads across Helen's well-ordered life like a stain, marking everyone who stands in its path. Lines from it echo throughout the novel (``I'm on fire. Is that too banal for you? It's not, you know. You'll see''). All who read it can't help projecting it onto their own lives. Helen, a charming but moody control freak who sells books by reckless flirtation (physical and intellectual), suddenly suspects everyone she knows of being in love with her. Could ``Ram'' be one of her doting customers? Or best friend Lucy, who manages the store? Or perhaps Johnny, the sexy, well-read college student she's employed for the summer? Inflamed by the possibilities of such a passion, Helen stumbles into a secret romance with Johnny. The author harps on the standard May-December themes, although not without humor (Helen watches MTV while Johnny reads Diana Trilling's memoir, each trying to cross the generation gap). Meanwhile, Helen is predictably shaken by the disruption of her comfortable life and by the ``desperate, uneasy bliss'' Johnny inspires. And of course her new interest in letters is reflected in the store's displays: She immediately layers the front table with...you guessed it, collections of correspondence. The intellectual pyrotechnics of Schine's previous book have given way here to frequent, but purely decorative, literary references; the pat plot betrays the author's low-key ambitions. Graceful but minor fiction.