"Laura Rider's Masterpiece" represents a departure for Jane Hamilton. Unlike her earlier works ("Map of the World," "The Book of Ruth"), this latest novel is a comedy, a satire filled with laugh-out-loud humor. Hamilton illuminates the implacable behavioral differences between the sexes, and the hilarious intricacies of reading and writing groups. If there is a purposeful idea grounding her story, it is perhaps that toying with other people's lives exacts a toll.

Like most of her fiction, the tale is set in the Midwest. Although Laura and Charlie Rider (Get it? Charles Ryder from Waugh's "Brideshead Revisited") have been married for 12 years, everyone assumes Charlie is gay. "Charlie emphatically was not a fag, swisher, fembo ... or any of the other names he'd been called since second grade," Hamilton notes. "It had always impressed Laura that a town that thought it had so few gays had so many labels for the aberration that was supposedly her husband."

Laura, who hopes to be a writer, becomes obsessed with Jenna Faroli, a radio talk-show host. When Jenna and Charlie become acquainted, Laura interferes, crafting romantic e-mails to Jenna in Charlie's name. Before long, Charlie collaborates with his wife in putting together increasingly flowery, intimate missives.

At the novel's conclusion Laura is writing a list of "what women wanted." What is No. 1 on her list? "What women wanted was always in flux. There was always something more, something new, something different to want. In her 20s, for example, Every Woman wanted to couple, to share, and if she was successful in that department, she wanted, by the time she was 40, to be left alone to watch Comedy Central."

KATHERINE BAILEY