Picture this: With all America and most of Europe watching on network television, Suzanne Somers clutches the folds of her Napoleonic gown and shrinks back from the slippery parapet of a gloomy castle.

The wind off the Scottish moors whips her blond hair and velvet bonnet. Edging toward her with a glinting rapier is J.R. himself, Larry Hagman, transformed into a brutish count and preparing -- with a "Dallas" smile -- to send Somers to the great drawing room in the sky.

But, thank heavens, help is at hand. Erik Estrada, in the gold braid and white uniform of a hussar captain, bounds up the castle steps, dispatches the villain with a show of white teeth and then smiles into the camera. He sweeps the countess into his arms and carries her off into a video sunset that dissolves beautifully into a cereal commercial.

And at home somewhere in Beverly Hills sits a television producer who swoons over backward in his designer jeans: Not from the romance of it all, but from the incredible overnight ratings.

This is only a Hollywood dream, and the stars have yet to be signed as the protagonists of a Gothic television series. But a sweet vision it is -- to the various producers who have mortgaged their souls to option romantic novels for the small and large screens.

In the past three years, a sizable chunk of the movie kingdom has been swept off its feet and carried away by the cagey ladies who cater to the final bastions of purity in America's jaded reading public -- the secretaries, housewives and even several thousand husbands who buy 20 million romantic novels each year.

The rush to romance began late in 1977, when former "Laugh-In" producer Ed Friendly bought the screen rights to every one of Gothicscribe Barbara Cartland's 200 novels. It reached a crescendo last week when Paramount Pictures announced that it had acquired the Silhouette Books' library of sigh stories for a series of films. So far, the trend has resulted in more then 20 projects in various stages of movies and TV development.

Not since Lillian Gish was preparing for "True Heart Susie" and Mary Pickford was rehearsing "Rebecca of Sunnybrook Farm" has Hollywood been so interested in virginity and the sanctity of marriage.

"We believe there's an incredible market out there for these films," says Barry Henspock, head of the film-production arm of Harlequin Books of Toronto (a corporate division of the Toronto Star Co.). "We have five or six projects in various stages of development with a sister company, Nielson Films. And we have a number of scripts to work with but no start dates yet." f

Paramount Pictures, involved in a joint production venture with Simon and Schuster and its subsidiary, Silhouette, likewise believes, to quote one executive, that "there's a hell of a market out there." Barrich Productions, the subordinate of Paramount that will make the films, is using a national reader survey and has found a "largecore market, predominantly female, plus quite a few men who are closet romance readers," according to a studio spokesman.

"But these people don't necessarily go to the movies now," said the Paramount executive. "We plan an unusual marketing technique in which the films will play area-by-area across the country rather than being released nationwide. Each area will have its own advertising blitz."

That is, Paramount will release the romantic films in much the same way that religious or family/wilderness films are offered to their entrenched audiences. "The films are likely to open in areas with the highest concentration of Silhouette novel readers," said Robert Weaver of Barrich Productionsd. " So don't look for the films to premiere in the big wicked city."

In other recent developments, Rosemary Rogers, queen of the somewhat heavier American romantic novel, has signed a major deal with the William Morris Agency and former romantic film heroine Joan Fontaine has begun a promotional contract with the Jove Paperback conglomerate to promote its new Borodine Historical Novels -- a deal which may ultimately include a TV project with Fontaine as the hostess.

This rush that has set Hollywood hearts aflutter is only a natural outgrowth of a worldwide Gothic book boom that began in 1972. By 1980 romantic novels accounted for 12 percent of all paperback sales in the world, and were being touted by Harlequin as "the third largest selling item" in American supermarkets.

Of all the publishers involved in the trend, Harlequin is the king; printing, according to its own estimates, 168 million copies in 10 languages and including millions of novels available only by subscription. This series, all published in Canada, and authored exclusively by British and Canadian authors, average 200 pages in length and revolve around career girls and wives making good.

Outside of Harlequin, the best selling companies in the field are Bantam and Dell, but Warner Books, Pocket Books and Fawcett Publishing all have romantic lines that are increasing each year.

British novelist Barbara Cartland has been in the game the longest, having started in 1923, but former Broadway actress Rosemary Rogers is the girl genius of the genre, selling at least a million copies of each of her 10 books.

Since nobody, especially Paramount, has released any production figures or film starting dates, some of Hollywood's visions of gold at the end of the Gothic rainbow may be little more than hype -- designed to gauge the interest of American audiences before spending any money.

Lending weight to this possibility is the recent past experience of Harlequin Productions and Ed Friendly -- both of whom had their first projects sunk by the weight of overblown romantic plots.

Harlequin tested the water first in 1978 by spending $1.3 million on one of the movies' first true virginal romances since the '40s. It was called "Leopard in the Snow," the story of a beautiful young heroine who gets her car stuck in a snowdrift and is forced to seek shelter in the Victorian house of a handsome race-car driver whom she eventually marries.

If you missed this one the first time out, don't feel bad. It was only released in a handful of cities, mostly in Canada, after audiences all but laughed it off the screen. "That one didn't set the world on fire," said Henspock, the man picked to replace the former production chief who left Harlequin after the "Leopard in the Snow" debacle.

Henspock believes that the first disaster taught the company a valuable lesson: That the films must be geared to the very specific audiences still interested in a lady's fight to retain her virginity until the right marriage. Harlequin's own readership surveys show that these women are married, aged from 17 to 39 and disillusioned by the promiscuity and violence of modern life. f

Friendly was the second major producer to test the Gothic waters with a $1.1-million television film, "The Flame Is Love." It aired on NBC in October of 1979, and placed third behind "Monday Night Football" and a special edition of "M*A*S*H*." Still, Friendly says, 24 million people watched it -- an encouraging sign. Nonetheless, he is now more careful when discussing the future of romance in the entertainment marketplace.

"This is an audience that is much more specialized, and 'm not at all sure that we will find that audience on prime-time television," Friendly said. "All the Cartland novels are incredibly virginal without even a hint of sex. And the mass audience may not be at all interested in that concept. We will probably have to seek out the right people by selling cassettes and leasing the product to cable outlets, because a mass audience that is still paying to see 'Deep Throat' out in the marketplace will never be receptive to something like 'The Flame Is Love.'"

Friendly believes he will have to go audience-shopping by taking the product out into suburban America. This, of course, is exactly what the publishers themselves have done with Gothic and romantic fiction during the last five years. More Harlequins and Cartlands are sold in supermarkets and by subscription than in book stores, and the sales in suburban shopping centers are 10 times those made in large American or European cities.

Pocket Books, which began the first-year Silhouette Series with an investment of $5 million, virtually designed its books around a readership survey taken to find out which elements of the romance genre appealed to the most readers. Ron Busch, president of Pocket Books, says that his editors found readers want the heavy romance inherent in the novels but they want it tempered with old-fashioned decency. "I live in New York," said Busch. "And there's nobody virtuous here. But I think that once you get beyond Hoboken there's a whole different world out there."

With this in mind, Silhouette has published a guide for prospective authors which says, among other things, that the heroine must be between 19 and 27; must be a virgin; should neither drink nor smoke; and must fall in love with a hero from 8 to 12 years older than she is. He should be handsome, says the guide, or at the very least -- "be quite virile."

Can this formula ever translate into mass screen audiences? "I'm not so sure," said Friendly. "Network television is so geared toward contemporary settings that it seems doubtful that a network will ever contract for a costume series. On the other hand, the formula may work very well in an afternoon soap format taped within a small indoor setting at a minimum of cost."

Some of the book companies, particularly Bantam and Dell, have realized the Puritan limitations of romantic fiction and are doing something about it.

Vivian Stephens, executive publisher of Dell's racier Ecstasy series, says she has "searched out authors who deal with women as they are right now. They don't just sit around mooning and waiting for a man to come along and change their lives."

This has helped, but Stephens has also added the one ingredient that has already interested two networks, ABC and CBS, in the Ecstasies -- sex. "We have added some explicit sex," said Stephens. "But it's gentle, with the emphasis on love and tenderness."

Stephens believes that romantic novels "can't go on pretending that the sexual revolution never happened."

The formula is already paying off; both in the market place and with network television executives. The first Ecstasy, "The Tawny Gold Man" by Amii Lorin, sold out this winter after a first printing of 90,000 copies. It was quickly optioned by ABC and requested by executives at CBS, although neither network has as yet committed money for a project.

"The people who can remember Ingrid Bergman and Charles Boyer or Rock Hudson and Doris Day relate to the new line," Stephens said. Stephens' romantic heroes have also been brought into the space age. One, for instance, is 38 and a Vietnam veteran. Another is so liberated that he lets the herioine go to work as a writer and quits his own job to stay home and take care of the kids.

Dell is also in the process of publishing a new line of ethnic romances with the first one, by a young black woman, set to come off the presses in February. Stephens has also bought works by two Chicano writers, a Chinese romantic novelist and a young Cherokee Indian writer. "And these stories are all charming and sensual," said Stephens, who is black herself.

After network executives had a chance to read four of the Ecstasy novels they scheduled meetings in Los Angeles and then ordered cost studies on possible TV movies.

The contemporary works of Rosemary Rogers have also generated interest at the networks with William Morris Agents working on deals that would involve both Rogers' past novels and original romantic scripts she has written directly for television.

But how much romance will the market bear? With Harlequin, Paramount, Friendly and William Morris talking romance -- and Warner Books and Avon still to be heard from -- a glut of product could arise much as it did with space films after "Star Wars." "I think the variety will be welcomed," said a spokesman for Harlequin. "Who knows? Suburban audiences may be able to go to the nearest supermarket and have as many as 100 video-cassette romances at their fingertip. I believe there's as much room for competition in the video product as there is in the book product. And competition certainly hasn't hurt us there."

A spokesman for Bantam Books, which publishes the Rosemary Rogers and Barbara Cartland catalogues, is not so sure. "First, I'm not sure that Hollywood producers will ever commit much money to romantic projects. We have found much reluctance throughout the whole industry when trying to sell any of our book projects. If it's not contemporary, they hardly look at it. And second, I'm not sure that the readers want to see their fantasies shattered on a TV screen. So much of the romance market really comes to life within a reader's mind. Let's face it, all the plots are the same."