Open Monday through Friday, 11 a.m. to 2 p.m. and 5 to 10 p.m., Saturday, 5 to 10 p.m. AE, MC, V. Reservations. Prices: Main courses at dinner $6.95 to $13. Dinner with wine averages $15 to $20 a person.

The fact that the story is familiar does not make it any less poignant. A cook -- a good cook -- sees a nearly empty restaurant in a worthy location and cannot resist trying to reverse that kitchen's fortunes. So in comes a new owner, full of energy and good intentions, redecorating and restaffing and rededicating this neglected site to unprecedented hospitality. But something does not click, either the location or the financial necessities or the employe pool or the insufficient professionalism of the new owner. And what could -- almost -- have been a good restaurant starts a downward spiral. Sometimes fate steps in to spin the tale in a new, happier direction, but it takes a restaurateur receptive to suggestion and a patient public.

Thus, the plot needs a little thickening at the Blue Danube. Its space was inhabited by a Vietnamese restaurant, not bad but outshined by nearby Chinese restaurants (as well as Italian and French). It faded away, to be replaced by these new Austro-Hungarian restauranteurs, who covered the windows with lace and brightened the plain room with canary yellow chairs and vivid blue quilted place mats. They piped in waltz music and stocked the kitchen with paprika, the authentic kind of paprika that is strong with flavor and aroma as well as color and fire.

Blue Danube is not luxurious, but it has a crubbed, colorful look with enough of a foreign accent to be a change of pace for Bethesda. The bread, a modest attempt at East European rye, comes covered with a Hungarian-printed cloth. The owners are attentive to the dining room, the ebullient hostess voicing her concern for her patrons in an elegant Hungarian accent. She not only asks how you are enjoying your meal, but inquires after each dish and begs you to have a pleasant visit. The single waiter -- so far the number of patrons has not warranted more than one -- serves with flair.

And nowhere in the Maryland suburbs is such a menu available, with the full complement of goulash and paprikash, schnitzel and stroganoff and sauerbraten, strudel and palachinta. Besides half a dozen appetizers (including spiced cheese and homestyle sausage, stuffed cabbage and herring) there are more than a dozen hefty main courses and Blue Danube Feast for two that heaps on Wiener schnitzel, roast meat, steak, stuffed cabage and sausage.

Choices are painful, until you discover that actually the kitchen is out of beef stroganoff and filet of sole and charcoal-roasted pork chops. It begins to dawn on you that with only three tables occupied, the kitchen cannot justify such a varied menu. Good intentions have been caught in the spiral.

Yet from the beginning it is obvious that the kitchen is capable. The stuffed cabbage, meat-and-rice-filled, is savory with sauerkraut and black pepper as well as that prevalent paprika undertone, and topped with a dollop of sour cream to mellow the blend. Marinated herring is firm and mildly vinegared, covered with crisp onions and sour cream. Goose liver pate' taste more like chopped chicken liver than goose liver, but is intriguingly smoked from bacon or well-cured ham. The sausage is mild but unusual. The goulash soup may not be as dense and thick as one expects, but it is a pungent broth with plenty of meat; the price, however, is high at $2.50. Only the spiced cheese deserved to be bypassed among appetizers; herbed Boursin or Boursault tastes better, perhaps because this one needed more time for its seasonings to ripen. But five out of six is a very high batting average for appetizers.

Main courses reveal the restaurant's vulnerabilities. Here ambitions have obviously been trimmed. The red cabbage intended to accompany many dishes has turned into sliced beets. The vegetables are frozen peas and carrots. Only the spaetzle, little homemade dumplings, carry out the character of the menu in the accompaniments.

As for the meats themselves, while none is outstanding, nearly all are appetizing. The Wiener schnitzel is very thin and crisply fried, not unlike one might find it in Vienna, with the breading fresh. A Viennese, however, would be offended at finding it served with sliced hard-cooked eggs rather than fried eggs on top, and would wonder where the anchoves went. The veal paprikash is tiny pieces of veal, but cooked to tenderness and well-flavored with a creamy though though overthickened paprika sauce. The sauce for the sauerbraten also is distressingly thick and starchy, but it is an interesting blend, tart, creamy and tomato-flecked, and the underlying meat is piquant from its long marinading and tender from proper cooking. The meat-filled palachinta are a disappointment; these stuffed pancakes must have been elicious before they were smothered in a starchy mushroom sauce overwhelmed by green peppers cooked to a mush. I'll take mine plain, thank you. These dishes, with slight variations, just about cover the menu, except for a steak and a "tyrol roast" that seems to vary at the chef's whim, once turning up as thin, breaded pork chops of no special distinction. There is duck. And duck cooked Hungarian-style is an exciting prospect. But it takes a brisk business to guarantee the freshly cooked quality of half a duck, and thus Blue Danube's version has been well seasoned but reheated to a sad stringiness. I would happily try it again an evening when the dining room was bustling.

That's the problem. Overthickening of sauces and misguided preparations here and there are easily corrected. But many of the flaws seem to be the inevitable scaling down for insufficient demand. And since many of the main dishes are $10 to $12, a diner's expectatious are bound to be high.

One can have a delightful evening, given the graciousness and the music and the Hungarian wines (mostly around $10 a bottle). Several of the desserts are more ornate than distingushed, but the homemade apple strudel is an aauthentic and pleasant ending. Blue Danube is not on the track of becoming an exquisite dining experlence, but it would not take much for it to become a valuable alternative to Bethesda's established restaurants. The question is who will take the first step, the management or the diners?