The career of Margaret Drabble has been dogged by questions of fate and chance. Was it fate that Ms. Drabble and her sister, A.S. Byatt, emerged from the smoke of Sheffield to become two of the most important British writers of the past 40 years? Was it luck?

When Ms. Drabble writes in “The Sea Lady” (Harcourt, 346 pages, $24), her 17th novel, of the “filthy little town,” Bonsett, where two similar siblings grew up, it reads as exaggerated self-description: “Some, in attempting to explain the extraordinary upward trajectory of Tommy and Ailsa Kelman, had ascribed it to the influence of Bonsett. … What fish would not attempt to leap from such a tank?” Like the Kelmans, Ms. Drabble and Ms. Byatt both won scholarships to prestigious universities. Both started writing in the 1960s, and while Ms. Byatt took extended breaks, Ms. Drabble continued to turn out novels year after year, steadily becoming a chief chronicler of English intellectual life.

The common criticism of Ms. Drabble, however, arises precisely from her sense of fate and chance. John Updike once called her “shamelessly dependent on coincidence.” But criticizing Ms. Drabble has proved difficult. Her techniques, unlike her themes, come from a different era. In the early 1970s, she wrote an admiring biography of Arnold Bennett, the Edwardian novelist long disdained by the modernists. Her deliberate anachronism, in both structure and style, still serves as preemptive protection: If one finds fault, Ms. Drabble can always respond, “Well, you don’t like the Edwardians either.”

In “The Sea Lady,” Ms. Drabble makes her method more explicit. The plot is intentionally unlikely. Two former lovers, Ailsa and Humphrey, successfully avoid each other for 40 years, until a university on the North Sea, where both spent their youth, separately invites them to accept honorary degrees. Ms. Drabble, instead of attributing this coincidence to chance, gives authorship of the scheme to a character in the novel: a mysterious “Public Orator,” midway between omniscient narrator and powerless observer. “The Orator,” we read, “hopes for coherence and conjunction. He does not wish to be obliged to force the plot. He wishes it to unfold itself as a plant unfurls its fronds towards the light, according to its nature.”

The novel never achieves that natural ease, and that seems part of the point. Ailsa and Humphrey first meet as children, during a summer on the coast. When they run into each other again, shortly after college, nothing comes of it. Only later, when Humphrey begins to establish himself as a marine biologist, and Ailsa, a pioneering feminist, invites him to see her burlesque show in London, does their past take on significance. As Ms. Drabble’s mouthpiece, the Orator, puts it:

If the story were unraveled to this point, to this knot, and then rewoven, it could be rewoven in many patterns. But we have to follow the facts. We cannot unweave, and remake. For chance and choice happen. They coincide, they coalesce, they mix, and then their joint outcome grows as hard and as fixed as cement.

Ms. Drabble, in an attempt to create a sense of life really lived, strews her fiction with coincidences, potentially both meaningful and meaningless. “After that,” her Orator says, “the actors have this terrible freedom. They can write their own script.”

Yet Ailsa and Humphrey never become free agents. Ms. Drabble’s voice dominates; her greatest strength as a writer, it drowns her characters out. Fine novels can be written that way, as Bennett and his contemporaries show, but they are the novels of a puppeteer, the characters “galley slaves,” to use Nabokov’s phrase. Ms. Drabble, in an attempt to justify her use of coincidence, tries to fashion it as a condition for freedom. But she can’t let Ailsa and Humphrey write their own scripts, and she chatters away to fill the void. That’s the unfortunate fate of “The Sea Lady,” and much of Ms. Drabble’s fiction: Neither fish nor fowl, neither strong in plot nor in character, it’s, at best, an experiment gone awry.

Mr. Petersen is a freelance writer living in Brooklyn.