It's been a tough year for Paula Zahn. In April tabloids reported that she and her husband of 20 years, multimillionaire real estate developer Richard Cohen, were calling it quits. Then, in July, Zahn resigned after six years at CNN—the day after the network announced that it had hired NBC's Campbell Brown to take over Zahn's nightly slot. Mercifully, both events seemed to proceed with remarkable civility—and then the ugliness started.

On Aug. 24 Zahn, 51, filed a civil suit in New York supreme court. In it she contends that shortly before marrying Cohen in 1987, she handed her financial affairs over to him; she is now demanding that he provide a detailed account of how he invested portions of her estimated $25 million in earnings over the last two decades.

Alleging that Cohen, 59, had spun "a Byzantine web" of investments and refused to disclose specifics, Zahn's attorneys say that she is now "readying to assume responsibility for her own financial security."

Two days later came the latest salvo in an increasingly bitter split: Two New York tabloids reported that a year ago, Cohen found a diary in which Zahn describes an affair with a married friend of theirs, agribusiness CEO Paul Fribourg. Fribourg could not be reached to address those claims, and Cohen will not comment, though a source close to him confirms that he found "a book" in one of the couple's three homes (they and their three children share a Fifth Ave. apartment as well as houses in Greenwich, Conn., and Aspen) detailing his wife's infidelity, and that the book's content is "lurid and disgraceful."

Zahn's agent Richard Liebner also refused comment. But it's clear that the events marked a rough spot for a couple who still haven't officially filed for divorce. "I only know Paula casually," says someone in her social circle. "But man, oh man, this is one horrible mess."