Too Much Happiness. Alice Munro. Knopf. 320 pages. $25.95.

Call it the Eudora Welty Effect. Four years ago, when Alice Munro hinted that The View From Castle Rock might be the last of her short-story collections, she set the hearts of graduate students going pitty-pat through the carrels of all the English Lit departments. Thesis time! Lots of references, to Chekov, to regionalism, to outsiders and isolates. All earned but beside the point.

Those of us outside the ivy are gladdened as we should be that Munro is back with her unique fiction. Unique in so many ways. Although we live in distracting times, reading Munro is an intensely personal experience. Her focus is so clear and her style so precise.

The nine short stories and title novella, each dramatically and subtly different, all have to do with lessons learned by the flickering light of mortality. And the lessons learned by narrators who find some comfort in looking back, despite the mass murder, the deaths and terminal illnesses, the fatal loss of innocence that are part of the narrative stream. There's no dearth of overt violence in this Munro collection, but it's almost always secondary, part of the frame but not the picture.

Dimensions, the first story, is not about the man who killed his three children or about the wife who visits him at the ``facility'' for the criminally insane but about how Doree comes to understand why, despite tremendous pain and the constant urging of the Greek chorus to ``put it behind her and move on,'' she still needs Lloyd.

The narrator of Child's Play, possibly the most disturbing and memorable of these stories, describes herself as ``an anthropologist by training though a rather slack one.'' She understands the trust women have for each other. ``It's supposed to have begun in those long periods of sitting by the campfire stirring the manioc porridge or whatever while the men were out in the bush deprived of conversation because it would warn off the wild animals.''

The anthropologist long ago at a summer camp bonded with a girl who shared a glimpse of her brother and his girlfriend, her brother's ``bare white bum'' with pimples on it. They have to drown that image, or whatever reminds them of it, before they go off to their separate lives.

Nita in Free Radicals assumed, as perhaps all reasonably content married people secretly do, that her mate would outlive her. But he went to buy a paint scraper and died of a stroke in the doorway of the hardware store. She has nothing left to lose. Cancer is gnawing at her liver. She's in remission, very much alone when a young man appears at her door saying he's supposed to look at her fuse box. Clearly he needs some food and the car abandoned in front of her house. I'm not going to rape you, he tells her, and then describes how he has just killed his father, mother and crippled sister, and walked all night. Nita believes him, but something stubborn in her, and maybe the recognition of the mesmerizing effect of story-telling, brings out her competitive spirit. She tells him a highly embellished story of how she poisoned the girl with whom her husband was once in love.

At its core the story is true enough, although the girl in question was her husband's first wife and no poison was involved or necessary. The conclusion of Free Radicals is extraneous. Nita's story is an atonement, what she needed to tell and what we wanted to hear. The splintered pole of memory is what sets a Munro story apart. Her characters are always seeing their past in a new light.

This is true even of Sofia Kovalevsky in the title novella, a Russian mathematician, widow, mother, novelist who, if truth be known, gives me a headache. Munro discovered her while looking for something else in the Britannica one day, she writes in her acknowledgment. Kovalevsky was a real person, and understandably Munro was curious about her. But Kovalevsky's short life was a dog's breakfast of higher mathematics, Communard politics, political marriages, family battles, class warfare, old teachers, dead sisters, suicidal paleontologists. We get too much of the externals here, although in time the story will fit into Munro territory, not as nuanced, but fully as daring and unpredictable as her other stories.

Betsy Willeford is a writer in Miami.