I THAS ALWAYS BEEN considered quite respectable for painters to cluster around a master and produce work that is frankly derivative. The school of Rubens covered the ceilings of Europe with angels and cherubim. The school of Reynolds populated the walls of the English country houses. Perhaps there should be less prejudice against derivative writers, for one of the values of the great writers should be what lesser talents can learn from their works. With one exception the novels selected this month reflect such a debt.

John le Carre, for example, is rightly regarded as a master of that school of espionage novels which regards the trade as a business as unglamorous and unsentimental as roadmending, and David Brierley is a British writer who owes much to him. Not only in style, but also in subject matter: treachery is afoot in the Service, spying itself is a dirty, wretched business, and there is no glamorous derring-do but only fear, suspicion and loss. The adversaries are familiar, too: the mastermind of the KGB pitted against the Service. All vintage le Carre.

The time is 1948, and the big bear (Russia) is poised to crush the city of Berlin -- the little bear. It is not easy to write a fictional account of an actual event; the risk of implausibility is high, and familiarity with the story can defuse the tension. But Brierley has written a credible account of the events that led to the Berlin Blockade and to the airlift of supplies into the city. He also gives George Orris -- the best man in the field the Depot ever had -- great plausibility. Smiley would approve of Orris, whose antennae can pick up the slightest discordant vibration.

Orris suspects that there is a highly placed mole in the Service when his group in Czechoslovakia is rounded up just as the Russians are taking over. He plans to flush out the traitor by drawing him to Berlin where he has been assigned, and to kill him there. While Orris closes in on his prey, the tension in the city increases as the Russians begin the blockade. They have relied on their British agent deliberately to misinform the Allied powers and expect no opposition.

There are enough convolutions of plot for a satisfying denouement, and Berlin just after the war with its burnt-out buildings and demoralized citizenry are convincingly evoked. Like many other recent thrillers the book seems to be written with an eye to the movie rights: chapters are brief, dialogue terse, scenes are short and change with dizzying rapidity, and the visual descriptions are as much aimed at the cameraman as the reader.