After years of insisting they would "absolutely not" write a book together, husband-and-wife team Jonathan and Faye Kellerman have sidestepped that vow while reaffirming their partnership: they've written two novellas together, with more on the way. The first pair, which feature different detectives and take place in separate cities, will be released in one volume under the series name Double Homicide by Warner on October 5. The reversible book will feature two different covers—one for each novella—with each author receiving top billing.

While Warner has published Faye's last two novels, Double Homicide will mark the first time Jonathan will join the house's list. "We see it as a way to get new readers," Warner publisher Jamie Raab told PW. "Jonathan outsells Faye. We're hoping that some readers of Jonathan's books will pick up Faye's." Ditto for Jonathan's long-time house, Ballantine, which will alternate publication of each volume in the series with Warner. "We're always working hard to find new readers," said v-p, editorial director Linda Marrow, who in fall 2005 will publish the next Double Homicide novellas. Rotating settings for the series may also help attract new fans: the first two stories are set in Boston and Santa Fe, N.Mex.

Are two authors, in fact, better than one? For Sessalee Hensley, fiction buyer at Barnes & Noble, the answer is a resounding "yes, as we found from Rule of Four and The Nanny Diaries," she said. At Amazon, where mysteries are one of the top-selling categories, senior books editor Ben Reese considers the novelty of the joint venture a cause for excitement. "I like to see new things, even if it's physically new, like the flip book," he said.

For their part, the Kellermans regard their experiment in co-writing as "great fun. It was a chance to create new characters and to travel," said Jonathan. He accounts for their decision to work together this way: "Things change. Creating new characters is a great tonic for two writers who write series characters."

The Kellermans will venture further afield than they usually do to promote the book, backed by what Raab describes as "a large six-figure advertising and publicity campaign." Though the couple usually limits their tour schedule, they've decided to leave their L.A. home base for New York; Boston; Houston, Tex.; Washington, D.C.; and San Francisco in mid to late October.

Just don't expect Double Homicide to affect other aspects of the couples' writing life. Faye plans to continue with her Peter Decker and Rina Lazarus mysteries; her most recent hardcover is Street Dreams (Warner, Aug. 2003). As for Jonathan, he plans to continue the Alex Delaware series, interspersing it with the occasional standalone. His next hardcover, Twisted (Ballantine), will go on sale November 23.