Another novel rich in emotion and rife with conflict from the prolific Roberts (From the Heart; Carolina Moon etc.), this sweeping saga of Northern California wine-making steeps the reader in a heady mix of sex, scandal and the excesses of the supremely wealthy. Sophia Giambelli, sophisticated head of marketing for the family-run Napa Valley winery, is the heiress to the Giambelli empire. She's often compared to her grandmother Tereza, La Signora, who still runs the business. The Giambelli holdings include the 100-year-old Castello di Giambelli in Venice, Italy; Villa Giambelli, operating in the Napa Valley for 64 years; and nearby MacMillan, a 92-year-old firm added to the family holdings when La Signora married Eli MacMillan. The wineries have always operated independently, but now La Signora announces that she wishes to merge all three, occasioning a major restructuring of responsibilities. She orders Sophia to replace Tyler MacMillan, Eli's grandson, and become the wine maker for both families' vineyards. The monosyllabic Tyler will spearhead marketing for the new joint venture. Laying the groundwork for heated fireworks, Sophia and Tyler fight not only each other but also a corporate saboteur who's being fed inside information. Dramatic personal confrontations are exacerbated by La Signora's designation of a new CEO, David Cutter, the only non-Giambelli to hold a position of power. Cutter brings his two teenage children with him to live in the winery guesthouse and immediately falls in love with Sophia's newly divorced mother, Pilar. Other juicy subplots involve manipulative mistresses, dilettante husbands and emotional Italian wives. As usual, Roberts provides plenty of intriguing background information, this time on wine making, and snappy dialogue. (Mar.) Forecast: Villains are easily discerned and susupense is at a minimum in this latest Roberts, but aggressive, savvy female protagonists should prove attractive to readers and enhance word of mouth. Overall, The Villa is vintage Roberts, a grand cru label for the bestseller lists; in expectation, the publisher is planning a first printing of 500,000. Literary Guild main selection; author tour.