Traces of love, not so long ago . . .

A soft color photograph of a smiling Martina Navratilova, encased in a silver and black Art Deco frame, sits on the window ledge of the second-floor office. Downstairs, in the near-empty study, the bookshelves are filled with the 458-volume set of Loeb's Classics, a $5,000 gift.

"Martina gave them to me for my birthday last year," says Rita Mae Brown. "It was the best birthday present I ever got."

Sure, it sounds corny, she says, "but when you love someone you love them." Her brown eyes are misting over. "I figure I signed on for life."

From the beginning, they were an odd love match.

Rita Mae Brown, dark-eyed beauty, feisty feminist, lesbian activist, acclaimed author of "Rubyfruit Jungle," and Martina Navratilova, young expatriate Czech tennis star with the winsome eyes and steely reserve.

Their private love affair suddenly became public property in the afterglow of notoriety prompted by Billie Jean King's candid statements on her own love affair with her former female secretary.

Brown and Navratilova first met at a luncheon in 1979, fell in love and last year bought a rambling, 20-room mansion on the outskirts of Charlottesville, Va., complete with tennis court, swimming pool and panoramic view of the Blue Ridge.

"It was a lunch that never ended," Brown said of their love affair.

They exercised in the $4,000 Universal gym in the basement, charmed guests at dinner parties, strolled on the lush grounds of their nine-acre estate and, in a bittersweet bow to tradition, wore thin gold wedding rings on the third fingers of their left hands.

And if anyone in town had any qualms about the relationship, they were soon won over by the tenderness between the two women who never sought approval, only a brief respite from the public glare of their shared celebrityhoods and careers. What better place than Charlottesville, that brick- and ivy-covered enclave of millionaires, horse breeders, intellectuals and writers, a town blessed with a British-style tolerance for eccentricity?

Rita Mae Brown had lived there since 1978. Before moving in with Navratilova, she had shared a house with actress-writer Fannie Flagg ("Coming Attractions"), in what Brown says was a business relationship.

Navratilova, who defected to America in 1975, fell in love with the rolling countryside, telling reporters the area reminded her of her homeland.

While the 24-year-old left-hander was busy becoming the top money winner on the women's tennis tour this year (earning nearly $500,000), the 36-year-old Brown, who often accompanied Navratilova on the tour, was finishing her fourth novel, "Sudden Death." The book, scheduled for publication next month, deals with the women's pro tennis circuit and, in particular, with a lesbian defector who bears a close resemblance to Navratilova.

But sometime this spring, their match was coming to an end.

Reporters began asking questions, especially after the Billie Jean King revelation.

Navratilova, a popular athlete with the sports writers if not the fans, made no secret of her relationship with Rita Mae Brown. But her long-awaited citizenship hearing was set for July and she was worried, according to one source, that talking freely about her bisexuality would hurt her chances of becoming a citizen. In news accounts, she also expressed fears that sponsors would start pulling out of women's tennis if there were more revelations of homosexuality.

Sometime after Wimbledon, where Navratilova was hounded by reporters about her sex life, the affair ended.

"She just walked out on me," Brown says now. "Can you believe it?"

Brown is sitting in the stark living room of their spacious English stone mansion, chewing gum and twisting the thin gold ring on the third finger of her left hand. Earlier that day, two of Brown's assistants packed up Navratilova's belongings, loaded them into a U-Haul and set out for Dallas to deliver them to the tennis star, who is now sharing a house with Dallas Diamonds' basketball superstar Nancy Lieberman.

"She Navratilova fell in love with somebody else," says Brown. "It happens all the time."

Not so, says her former lover.

"That's not the reason we broke up. In her eyes, maybe, but not in mine," says Navratilova. Reached in Dallas, Navratilova says that Nancy Lieberman is "straight" and that the two women are just friends. "My personal life is nobody's business," Navratilova says angrily.

As for the split with Brown, the tennis star says, "We weren't happy . That's the reason we broke up."

Brown shrugs her shoulders. No, she says, she is not bitter. But the end came as a surprise. "For me it did," she says. "I think people have no control over their hearts."

There is no such thing as security, she says. "Security is when you're dead."

She is small and dark, with enormous brown eyes, freckled skin and wisps of short brown hair falling over a high forehead. A young Natalie Wood, with street smarts and small crow's-feet etched into her angular face. She wears a white silk blouse, diamond necklace, gold Rolex watch (a gift from a female admirer), and gold hoop earrings. Her toes, peeking out from white sling-back heels, are painted rubyfruit red. She looks, contrary to her literary image, vulnerable and fragile, engulfed by the vast emptiness of the enormous rooms.

Yes, she says softly, she would take Martina back.

Can this be the same Rita Mae Brown who shocked the literary scene in 1973 with her sexy, sassy semi-autobiographical novel about growing up gay in straight-arrowville America? The same Rita Mae Brown who got kicked out of NOW? The same outrageous, reckless Rita who delights in perpetuating her reputation as Molly Bolt, the illegitimate brat boy-woman who came into this world, not with a cry, but with a Bronx cheer?

"Love is the wild card of existence," she says