Inconsequentiality has its wiles, but, rather quickly, "Love in a Cold Climate" quaints itself dizzy. The eight-part "Masterpiece Theater," premiering Sunday at 9 on Channel 26 and other public TV stations, was adapted by Simon Raven from two Nancy Mitford books, "The Pursuit of Love" and "Love in a Cold Climate." Obviously the worse of the two titles was chosen for the Thames Television production.

In chapter one, "Child Hunt," it is 1924, and we meet, under another name, Mitford's peculiar aristocratic family, the most dottily towering member of which is Lord Alconleigh, played as a blustering human bloodhound by Michael Aldridge, who is ferociously commanding in every scene in which he appears.

Lord Alconleigh is quite funny when he storms into a room and bellows, on the subject of a handsome dog to whom he has taken a disliking, "I thought I told you to leave this sewer of a labby in the stables!" But in the second episode, which takes place six years later, he is less funny caterwauling about foreigners, "frogs and wops," that are among his gallery of impertinent menaces. Judi Dench makes something quietly heroic out of Lady Alconleigh, who puts up with these carryings-on and knows just how to deal with them.

The most attractive characters are the little girls who look upon the adult world with wry patience and generous tolerance. It's almost a pity to see them grow up, as it usually is with little girls and little everything else, for that matter. Lucy Gutteridge as Linda Radlett and Rosalyn Landor as Polly Hampton exchange the kind of confidences known only to young ladies, the sort of privileged communication mere men can only regard with jealous awe.

Donald McWhinnie, the director, doesn't seem possessed of any originality, or of a sure hand at mixing film (the exteriors) with tape (the interiors), and occasionally sports a mean streak, as with the way he shoots a weary coming-out party in the second chapter. Alistair Cooke introduces this "Masterpiece" (here the term is stretched beyond all decency) sitting in an artificially sunny, plant-filled conservatory and looking for all the world like Henry Higgins come to call at mother's house.