The Transformation of a Strangling Soul : THE FREQUENCY OF SOULS by Mary Kay Zuravleff; Farrar Straus & Giroux $23, 243 pages

It is not so much that George Mahoney is a nerd, as that, like the hermit crab, he has crept into an available carapace for concealment and protection. His youthful scientific passion for dinosaurs was blighted by a mean mother. Each morning he dons clip-on bow tie and pocket pen protector to go to work designing ice-makers and butter-softeners for a refrigerator company. Each evening he goes home to be dominated, entirely nicely, by his enterprising wife, Judy.

“Passive-passive,” is Judy’s regretful verdict. George is “someone who does nothing because of self-interest and holds it against no one when he is ignored.”

Because Mary Kay Zuravleff’s “The Frequency of Souls” is a fable, of sorts, an angel of sorts arrives to work a transformation. Niagara, George’s new co-worker, is a genius who has taken the refrigerator job to pay for a giant radio dish. Its purpose is to pick up the faint signals, which, she is convinced, people continue to emit after they die.

If there can be dinosaur fossils, she appeals to George’s long-submerged passion, “why can’t there be audible fossils of our ancestors? You were a budding paleontologist. I’m listening to the bones of souls.”

George is entranced, not so much by his office mate’s particular project--though it does show signs of working--as by the eruption into his life of the wild spirit of scientific exploration that he had retreated from. Her excessiveness explodes his cautiousness. It also explodes his lust even though Niagara is 6 feet tall, husky, ungainly and partly deaf; and wears thick glasses and homemade dresses that resemble couch upholstery.

“Frequency” tells of Niagara’s comet-like transit through George’s quiet bit of galaxy. After a bit of mild ardor--a firestorm to him--she transfers her absent-minded yens to a fellow genius, and departs for a university research post (though it will be in ethics or religion rather than science).

George’s own orbit is not shattered but it is altered and considerably speeded up.

There are many nice touches in the book. The best is George’s devotion to his son, Harris: overweight, a compulsive eater, and the untidy, awkward scientific original his father never dared to be. His mother tries to smooth him out, groom him for success, thin him down. The child declines her offer of carrot sticks as a substitute for junk food: “No thanks. I’m trying to get large enough to create my own weather system.”

Niagara’s eruption doesn’t turn George into a scientific creator; but it does give him the insight and strength to discard his passivity and defend Harris from Judy, his ambitious, though entirely likable, mother. This is fine, up to a point; what is less fine is Judy’s dulcet acquiescence in the course of an ending that ties up entirely too many things far too neatly.

Zuravleff has the makings of a decent, if not very original parable, but she only partly manages to assemble it. We are interested in seeing how George’s worm will turn; but the childhood scenes that are used to explain him are second-rate and obvious. Niagara’s extravagance is picturesque, but she never quite comes together as an angel, let alone a character. Despite the details of her odd persona it is hard to get even a physical impression. I keep envisioning Janet Reno but I’m sure that’s not what the writer has in mind.

The writing frequently sags from its brighter moments. Niagara’s mishearing of words--George mentions his fillings and she hears “feelings”--does not make top-grade humor. George’s resolution, at the end, to amend his life is a lead balloon: “He would endeavor to wonder; he would allow himself to err.”

Beyond this, Niagara’s experiments with the voices of the dead are recounted in detail but with insufficient skill or charm. Since this is a part fantasy it is not necessary to make us believe it. But it is necessary, at least, to make us want to believe it.