The plot has all the ingredients of a pulp best-seller—a rancorous conflict waged on the New York literary scene by two power brokers who had once been in love but who are now privately and professionally at war. But don't try to sell the outline to Richard Snyder, the chairman and CEO of book-publishing conglomerate Simon & Schuster, or to Joni Evans, his estranged wife and the newly appointed publisher of Random House. This melodrama would be too hot, and too close to home, for either of them to handle.

Once they were publishing's most awesome duo. A titan of the blockbuster, Snyder, 54, helped put Bob Woodward and Carl Bernstein on the best-seller lists. Evans, 45, a tough, talented editor, scored with such books as Mario Puzo's The Sicilian, Jeffrey Archer's First Among Equals and Helen Gurley Brown's Having It All. Together they led S&S to fiscal triumph, hobnobbed with the cream of the literati and earned more than $1 million a year between them. Then came a sequence of events that rocked the literary world. Last year Evans separated from Snyder after eight years of marriage. Then, this September, she left S&S after 13 years of service and only six weeks later replaced Howard Kaminsky as the publisher of Random House, Simon & Schuster's archrival.

Now sitting in high-rise offices on opposite sides of Manhattan, Snyder and Evans are sparring for megabuck books and writers. Publicly they treat each other with the studied respect of professionals. In divorce court, however, the gloves come off. Both are fighting over a reported prenuptial agreement and millions in assets, including Linden Farm, a 75-acre Westchester estate with a 14-room Normandy chateau, rock-lined swimming pool, tennis court and conservatory. While neither Snyder nor Evans will comment, those who know them call the combat ugly. "It's bitter, full-scale legal warfare," says superagent Mort Janklow.

Evans was born for the battle. "She is driven, dedicated and absolutely tireless," says gossip columnist Liz Smith, a friend of the couple's. Those qualities, combined with a tart tongue and a spontaneous combustion temper, brought Evans to the top of the paper heap. Daughter of a wealthy New York textile importer, Joni Goldfinger received a B.A. in English at the University of Pittsburgh in 1963 and became a secretary to the book editor of McCall's. Four years later she married Richard Evans, who was working toward an M.B.A. at Harvard. Joni began writing and editing for Writer magazine, as well as reading manuscripts for the Book-of-the-Month Club. In 1968 the couple moved from Boston to Manhattan, where she worked as a manuscript reader, and later an editor, for William Morrow. In 1974 she jumped to Simon & Schuster as subsidiary rights director and a year later ended her marriage.

Enter Snyder, the less-than-humble boy from Brooklyn. Ruthless and abrasive—"even by the standards of Manhattan," in the words of one agent—Snyder graduated as an economics major from Tufts University in 1955 and rose from an assistant marketing director at Doubleday to publisher of Simon & Schuster in 11 years. When Evans arrived on the scene, Snyder's 11-year marriage to Otilie Freund, which produced two children, was shaky. "Snyder is competitive and always slashing, slashing, slashing," says Susan Brownmiller, whose 1984 book, Femininity, was edited by Evans. "He plays at fencing all the time. But Joni had that kind of femininity where she could play up to him—soothe and mollify him and flirt. So the relationship was good for a number of years."

Creating a minor publishing legend, Evans and Snyder were wed during a lunch break in 1978 and honeymooned at their favorite spot, the S&S offices. "Both were genuinely in love," recalls Dan Green, head of Weidenfeld & Nicolson publishing house, who worked with them at the time. "Dick was a fabulous tutor for Joni. Both sparked one another." Adds Jeffrey Archer: "Dick was at the top of his profession when Joni was only halfway up the ladder, and she learned a tremendous amount from him about the corporate and financial side of the business."

Both workaholics, Snyder and Evans meshed well at the office and staged elegant dinner parties in their East Side town house. They only seemed to relax during weekend retreats to their country estate, which became a symbol of their joint success and love. "The house is a dream," says Helen Gurley Brown, "quite baronial with deer on the lawn. They were spending every penny they had fixing it up. I can imagine them both wanting that house."

Ironically it was Evans' devotion to her job that began to spoil the relationship. In 1979 she started her own imprint for S&S—called Linden Press in honor of the couple's country home—and went on to build it into a multimillion-dollar business. "She was involved with it day and night," says Susan Brownmiller. "It got to the point where he asked her to turn it off. He would want to go to a movie. She'd look at him and say, 'You go to a movie! I want to work.' He'd say, 'You're not the woman I married.' It went on from there." They finally separated. "It was a mutual break," says a friend of Snyder's. "Professionally he thought she was aces. But Evans wasn't being attentive to Dick's needs anymore."

While Evans moved into Manhattan's Olympic Tower, and Snyder into an East Side apartment, both remained at S&S, thus beginning one of the most bizarre and tense working relationships in the annals of publishing. The split started as amicable and private, but as the court battle began—and details of it appeared in the press—the couple's animosity escalated, often erupting in hostile outbursts. "I heard the meetings at Simon & Schuster got pretty bitter," says an acquaintance of the pair's. "How Joni stayed there under the circumstances is beyond me."

Evans found a way out in August, when Random House Chairman Robert Bernstein offered her an imprint at his company. Her exit made headlines, but what took place last month created even bigger news in the publishing world. Bernstein, 64, forced his heir apparent, Howard Kaminsky, 47, to resign and named Evans as the new publisher. "I was in Rome when I was called home to talk about it," says Evans. "I was as stunned as everyone else."

Kaminsky claims he wasn't completely surprised. "We had a difference in philosophy," he says, referring to Bernstein. Says a former Random House editor: "Bernstein became fixated that Howard was trying to pull something." Another former editor adds, "Tension was building. They both play hardball."

Evans is seen as less of a threat to Bernstein's power; he hasn't anointed her as his successor nor given her all of Kaminsky's duties. "She's going to be more a publisher-editor than a publisher-administrator," says Bernstein. "She'll be working more on manuscripts, and therefore I think the Random House imprint is going to be considerably stronger."

It already is. Evans has signed former S&S writers Mario Puzo and Ann Beattie (Where You'll Find Me, and Other Stories) to new Random House contracts. More could follow. Meanwhile, Snyder, once dubbed "the Gaddafi of publishing," can be expected to retaliate. The stage is set for an all-out, Macy's-and-Gimbels, no-holds-barred clash. "And nobody has to feel sorry for either Dick or Joni," says Liz Smith. "I think they're pretty evenly matched." Jeffrey Archer agrees. "If they arrived in the jungle together," he says, "I'm not sure which one would be skinned."