You don't have to be a certified Anglophile to see the comic possibilities of a novel about a party of larky British artists visiting the Soviet Union on a cultural exchange tour. Such a tour is the stuff of Beryl Bainbridge's ninth novel, "Winter Garden," and right away it has to be said that she is a very funny writer. Several quarts of vodka into the tour, at a luncheon given by the Moscow Artists' Union for the visitors, occurs this exchange, when the Englishman Douglas Ashburner gives way to an excess of amiability: "In a harangue on property values in London and the rise in the cost of living in relation to workers' raises . . . he realized he was actually implying that the system was unjust and the investing of money immoral. . . He couldn't think what had got into him. He had never been known to vote Labour. . . Moments later, hearing a [Russian] telling Bernard that his wife kept a servant, and hardly able to believe his ears, he cried out 'A servant, a servant!' in tones of such critical severity that Bernard leaned across the table and ordered him to belt up. 'You're overdoing the flat cap and brown boots number, mate,' he hissed."

Bainbridge specializes in paragraphs like this -- her sentences progressively pile up to a concluding detonation at once absurd and astonishing, a device that makes reading "Winter Garden" a delight. Moments after Ashburner's faux pas, his compatriot Ednid Dwyer allows their host, Karlovitch, to put his arm around her. "Ashburner wouldn't have thought her the loose type, or Karlovitch for that matter, though these days that sort of thing was rife in every camp." The lovers steal away because sly Enid has expressed "a wish to look more closely at a painting of Lenin inciting some shipyard workers to rebellion." The hapless Ashburner is soon alone with the Russians, "obliged to enthuse, single-handed, over a series of raised reliefs of naked women with rippling hair." Not even Evelyn Waugh in full flight could have exploited this encounter of Briton and Slav to deadlier effect.

By now we should be used to Bainbridge's exotic powers to invention. Her last novel (in point of composition, not publication) was the outrageously original "Young Adolf," in which a 21-year-old, rather Chaplinesque Hitler turns up in Liverpool in 1912. Earlier, there was the much acclaimed "The Bottle Factory Outing," whose migrant Italian workers turn a holiday into something more than a morris dance around a tea cosy in the vicar's garden -- what we are used to from Barbara Pym. Bainbridge uses foreign, that is to say continental, characters in farcical situations to heighten the eccentricities of her British characters. This is something new in postwar English humor, although reminiscent of Waugh's portraits of non-white characters in his earlier novels like "Scoop" and "Black Mischief."

Alas, Bainbridge is no Waugh. In "Winter Garden" -- the title could be construed as representing either the snowy wastes of Russia or Ashburner's wife's back garden, "so called because even in summer it lay as dark as the grave . . . further proof of an abhorrence of sex" -- the humor is delicious but the potentially dazzling possibilities of the story frizzle out in an over-indulgence of parable.

Ashburner, the sole non-artist in the party, has told his wife that he is going fishing in the Highlands. Actually he's accompanying his mistress Nina St. Clair on the Russian tour ("Nina had bold blue eyes, black hair that she sometimes plaited and legs like a principal boy. She had never been known to lose an argument"). But Nina disappears soon after their arrival in Moscow, and Ashburner wanders throughout the rest of the novel like Christian in the Slough of Despond. At the end, he appears at an unnamed building on Dzerzhinsky Square in quest of Nina and is arrested as a spy, incriminating papers having been found stuffed in the canvas case of his fishing rod. The building presumably is the famous headquarters of the state security police, the KGB, though Bainbridge never tells us so. Concludes Ashburner: "Even the man who is sensible and composed . . . must pale before life's contradictions." The moral seems pointless, and it is in fact the reader who pales before this slight novel's ultimately cruel inanity. Bainbridge, possessed of so evident a talent for the farcical, should stick to her main strength.