MARY CUNNINGHAM and William Agee were one of the most dazzling executive teams to share a corporate jet before Agee publicly disavowed romance as any part of the motive force behind her meteoric rise at the Bendix Corp. It was a burst of candor that backfired two weeks ago into a major national news story, creating "excessive attention" and "false innuendoes" which, Cunningham said, made it impossible for her to carry out her new duties as vice president for strategic planning. She knew she would have to resign. But how? Her own strategy was brilliant.

First, Cunningham offered to take a leave of absence. Since the Bendix board of directors had recommended her promotion as a way to stop office gossip, Mary was putting the ball back in their court -- presuming they would go public with a full vote of confidence in her. They did. With her reputation restored, Mary Cunningham waited 10 days, and then resigned.

Where does this leave men and women of the future who would aspire to a close working relationship at the top? Were Agee and Cunningham sabotaged by envy and brought down byageism, sexism and corporate game player? Or is she something more?

The irony of the situation was summed up by a top financial-world executive who knew of the intensely religious background that had molded Mary's missionary zeal:

"If Mary Cunningham was trying to capture anything from Bill Agee, it wasn't his heart -- more likely she wanted to save his soul."

I tended to agree. Mary Cunningham is someone I knew quite well from taping a long interview with her about her background and goals 15 months ago, while researching a book still in preparation. For that reason, despite a company ban prohibiting further comment, both she and Agee agreed to see me to round out the story. What follows is an exclusive account of the rise and sudden deceleration, and recent recovery, of Mary Cunningham's rocket to success.

Mary Cunningham came across the radar screens of the corporate recruiters like a comet. Everyone who interviewed her had the same impressions. "She's brilliant." "She's intimidating." "She's aggressive." "She's beautiful, too!" And everyone wanted to know the same thing. "What drives her?"

Teams of interviewers picked through her braion that spring of '79 before she graduated with breathtaking credentials. She was a Phi Beta Kappa philosophy graduate from Wellesley, and then one of 30 out of 800 business school students elected to Harvard's Century Club as leaders of tomorrow. In her second year at Harvard Business School she took a course overload, carried a job, created an exam review program for first-year business students and sailed out with honors at 27.

"If there's a woman in America who can become chief executive officer of a Fortune 500 company anytime in the next 10 years -- on ability -- it's Mary," the dean of HBS, James Heskett, had told the women's student association.

The corporate world drooled. Karen Walker, herself one of the highest-potential female middle managers at Bendix, lit up when she met Mary on a recruiting swing. "She's super-quick, articulate, very ambitious and --" Walker groped for the right words to convince her company a position should be created for Cunningham -- "she goes out of her way to do special things for people."

A team from Salomon Brothers went over her meticulously and concluded she was "awesomely motivated." But they couldn't figure out why. "Does money motivate you?" they tried. "Would anything keep you working until one in the morning?" Definitely, she said. "What is it you are really trying to accomplish?" they kept asking.

"One day I will have something to say," she replied. "I'm not ready to say it yet."

It made Mary Cunningham smile. They couldn't slot her, couldn't say, "Oh, yes, you must be from Darien." Recruiters found her background, well, quaint . . . Hanover, N.H., no money or family connections, drawn toward philosophy from an early age, and what was this about being raised by a mother and a substitute father who was a monsignor?

Offers from the financial world started at $47,000. Goldman sachs matched Morgan Stanley, trying to attract her to their mergers and acquisitons departments; Baine & Company matched Braxton and McKenzie in consulting. Mary kept them all dangling. Try as they might, none of them could figure out what makes Mary fly ?

Money wasn't what she had on her mind. Lord no. What she wanted was to do good.

Her clearest memory . . . the child Mary is 5 1/2. Blond, angelic. Her mother and Father Bill are outside in the car about to make a momentous move. A shroud of fog lies on the fields where night has not quite slunk away for day. "I left my dolly," Mary cries out. "Can you go back for my dolly?" Father Bill says yes. The little girl climbs the stairs and passes her real father's room and after finding her doll passes her father's room again. He calls out, "Is that you, Mimi?" -- her mother's name. The moment opens up and nearly swallows the little girl. She longs to answer her father but senses she must not. At the top of the stairs she stands for an eternity hoping that he will call out her name . . . Mary don't leave me . . . but he does not. Mary runs down the stairs and into the car in which her mother will drive away from her father forever. From that day until she turns 21, Mary will deny rality and tell anyone who asks, "My father is dead."

The youngest born into an Irish Catholic family, Mary Cunningham had watched her mother suffer the last of an 18-year marriage to a charming alcoholic. Their only son was crushed to death in the father's recklessly driven car. It took that shock to challenge the mother's belief that to accept one's trap made one a better person. When Mary was 5 she wrote her mother a secret note:

You make your own good, was the gist of it.

Beginning even then to reject the passive, victim orientation of many women, Mary soon took a precocious leap of development. 'it happened when Monsignor William L. Nolan (now chaplain at Darthmouth College) took her under his wing and planted the idea that she could be an active reformer. First, Father Bill had to convince Mrs. Cunningham to leave her husband. Mary was sure even then that Father Bill loved her mother. But another tragedy of the heart had long ago shelved their love on a purely platonic plane.

As Mary tells it, William Nolan had introduced Mary's mother and father.

Her dad was a dazzler, very much the extrovert in contrast to shy teenage Bill Nolan, who was certain the two had fallen in love and there was nothing for him but to enter the seminary. For a lark, Cunningham suggested to Mimi on the way home from their honeymoon that they stop and see Nolan. The new bride and the bashful semimarian caught each other's eye and at once they knew. They had both made a mistake.

Two decades later, shortly after the tragic death of Mary's brother, Father Bill came back into their lives. He still cared for Mary's mother, he said, but of course could not marry her. He offered instead to become the legal guardian who would help her raise the two remaining children. So it was that Mary lived our her childhood with her mother, sending her notes of assurance that "You haven't done anything wrong" and waiting in a fever of excitement for the visits from Father Bill. They would walk the beach together and talk about life. Once she told him about reading Socrates; when it came to the part about Socrates discovered his "mission" she became so exhilarated she had to put the book down.

She confessed that two different selves seemed to inhabit her. One was practical Mary: fearsomely motivated to achieve so that she could never be rejected again (feeling that her real father had rejected her). Practical Mary competed to be the brightest or best even though it consistently set her apart as the detested overachiever. But there was also angel Mary, levitating on her ideals to the point where she saw always the good in man's nature. How she yearned to capture that spirit, write about it, send out the good news. Father Bill said she didn't have to deny either side. She could become a practical idealist.

"The judge," she was nicknamed as a child. But her solemn face softened into a young woman with clear eyes, full lips, a high devout forehead, a cascade of strawberry blond hair and a perfect size 6 figure. She was beautiful. Notwithstanding, Mary suffered her greatest disappointment at 17. It was then she realized there was no way she could be a priest.

Very well, she would work her secret priestly mission in what she perceived to be the most decadent corridor of the culture -- corporate America. But first she would need a cover. Business? Law? Politics? After finishing Wellesley she decided on law school in the Midwest.

The night Bo Gray came into her life she fell in love on the spot. They met at a party and matched outrageous philosophical repartee all night. Here was a black man, strong and tall and 12 years her senior, product of a protected background and now solid middle management. Bo carried the card of a vice president of Chase Manhattan in New York: Howard Gray. Mary had begun almost to despair of finding a man to fit Father Bill's shoes. Bo, in her opinion, was "greater than his white counterpart, because he had overcome so much more." Yet it was almost as if she had married a challenger to Father Bill; for a proper white Catholic girl Bo, being black, was even more of a forbidden sexual partner than a priest.

She and Bo went up against bigotry with wit. It was morally bracing but personally a real drag. Mary couldn't ask Bo to subject himself to living in the Midwest, where one night a motel owner had refused even to rent them rooms. So she gave up law school to marry him and they moved to the fringes of Harlem. Had she not found a Bo to marry, she might never have broken away from the monsignor.

"Father Bill," she phoned six months later. "I've just been made a financial analyst at Chase Manhattan!"

"Are you being a good wife?" Just like Father Bill. He had never praised her, not once, and neither did her husband. One could hardly find a more powerful motivating force: striving to be perfect in order to earn the love of these men. Since they would never praise her, she could never exhaust her efforts to be better.

Twice, at Chase, she found herself becoming part of a less-than-ethical approach to make a deal work. With her job on the line she found innovative alternatives without losing anything on the bottom line. She did not know if this would always work.

More leverage was what she needed: the chances to set policy rather than relying on her nimble mind or persuasive charms. And for that she would need power. It was more important to her than money, she decided. But first she would have to make of herself a perfect marketing package.

She would go to Harvard Business School.

So it was that Mary Cunningham constructed herself along the line of a biplane. But with two very different sets of wings. The passionate angel's wings above worked day and night at sweeping the dust off men's souls, while below, strong and sleek, beat the wings of pure ambition.