THE ROMANTIC ENGLISHWOMAN is a minor but interesting contribution to the growing number of films about upper-middle-class fears and fantasies, particularly those related to sex and marriage. This film treats some of the same discontents as Scenes from a Marriage or Sunday, Bloody Sunday, but it is closer in conception to something like The Discreet Charm of the Bourgeoisie, which makes more sense on the psychological than the plot level. Unfortunately, it lacks the fanciful and humorous elements of Discreet Charm, but it has a few ideas of its own to offer.

The bourgeois couple of this film is played by Glenda Jackson and Michael Caine. Their performances are good, given the built-in limitations of the roles--this is not an actor's film. The plot is not the strongest point either: Jackson, bored with her perfect husband, adorable son, and luxurious suburban house, takes a little vacation at a continental spa, perhaps in search of some discreet adultery. There she encounters a young man (Helmut Berger) who claims to be a poet. Actually, he is a sort of well-tailored adventurer with a talent for playing the gigolo, and a lesser flair for dope-running--he caches a large supply of cocaine on the roof of their Baden hotel only to dash up there during a rainstorm in time to find thousands of dollars literally going down the drain. He follows Jackson back to her home near London, where the husband, a pulp-fiction writer, dying to discover whether or not they are having an affair, invites the young man to stay with them indefinitely. In setting up this menage-a-trois, the husband, working on a screenplay about middle-aged infidelity, eventually brings about the events he supposedly fears: his wife, who had committed no infidelities in Baden, seduces the "poet" and then runs off with him.

CAINE AND JACKSON are not a typical middle-aged couple: they are intelligent, articulate, cultivated and rich. They are sexually uninhibited--when a neighbor interrupts them making love on the lawn they are completely unperturbed. He is successful and likes his work; she seems unconcerned by her own lack of a career. only problem with their lives, seemingly, is its lack of problems. They react to this situation in three ways--boredom, guilt about their affluence, and obsession with the nastier aspects of life even material security and good taste cannot overcome--loss of control and death. The wife is haunted by the fear that something will happen to her five-year-old. The husband refuses to fly, and is horrified to find that she took a plane to Baden. Unfortunately neither one is very sympathetic to the other's fears; instead of comforting each other they suffer separately.

The young man unerringly plays on all of their weaknesses. He is mysterious, vaguely dangerous. They know he is not a poet--he confuses the husband, Lewis Fielding, with the author of Tom Jones--but that is about the only thing they know. He is intriguing to them in their boredom and he is a sop to their material guilt. Berger bluntly tells the husband that he, the stranger, is doing them a favor by sponging on them and thereby quieting their uneasy consciences. In addition, this complete intruder appeals to the husband's fears about his wife's faithfulness. Fielding the writer would rather make the adultery come about in a situation he can manipulate, rather than endure the passive uncertainty of waiting to find out.

THE sensitive, slow-paced direction of Joseph Losey is well suited to a film that operates more on the level of fear and fantasy than of realistic plot development. The Romantic Englishwoman is extremely well-edited, revealing aspects of the story almost impossible to capture in another medium. In Baden, for example, the gigolo follows the wife from a casino to her hotel. As she reaches the lobby, the telephone is ringing--it is her husband, calling to check up on her for the nth time. She is annoyed, and short with him: "The lift is here. Good-bye." She gets into the elevator with the stranger. The camera cuts to a scene inside the ascending lift, where two people are beginning to make love in the flickering half-light. The wife's eyes are closed, her neck arched back. We cannot see the man's face clearly. The scene shifts abruptly the disgruntled husband in bed, worrying. We realize that the previous scene is only his fantasy, not the real event at all. Back to the hotel in Baden: he invites her up to his room, and she turns him down. This kind of cross-cutting is used to good effect throughout the film. The audience momentarily experiences the characters' uncertainty as to the boundary between imagination and reality; we understand them much better as a result.

The screenplay by Thomas Wiseman from his novel of the same name, with the collaboration of playwright Tom Stoppard, is not as subtly revealing of character as the direction and editing. In fact much of it is irritatingly banal--the few funny moments, presumably contributed by Stoppard, seem like the last-minute contrivances. Comic relief is pretty welcome during this film, though, no matter how forced it may be. When the wife and the gigolo finally fulfill their artificially arranged estiny by running off together, the husband tries to track them down. He notices that a mysterious car has been following him, and suspects that enemies of the gigolo are counting on him to lead them to their quarry. The husband has the quintessential bourgeois quality, niceness; he doesn't want the gigolo to die, he just wants his wife back. He stops to talk to the men, tries to persuade them to give up the chase. "Oh, but you don't understand," says their leader, perfectly deadpan. "I represent the Irish Sweepstakes. He has won, and I am trying to notify him."

FOR ALL ITS flaws and eccentricities, The Romantic Englishwoman is an interesting and intelligent film. In subordinating narrative realism to the psychological dynamics of a marriage, this movie occasionally evokes the inevitable fears more sharply than the discursive Scenes from a Marriage. It's all somewhat abstract, but the romanticism of this particular Englishwoman and - man is, after all, only a state of mind.