In 1984, William McPherson published his first novel, Testing the Current, a brilliantly written account of a year in the life of Tommy MacAllister. Set in 1939 in Grande Riviere, Wisconsin, the novel chronicled a child's, a family's, and in a sense a whole community's fall from innocence and did so by means of a Jamesisn attention to nuance and detail and a precise, ironic dissection of the upper class worthy of Edith Wharton. Though told from the perspective of a bright and sensitive 9-year-old boy, Testing the Current provided a coherent, unified vision of life as it was lived at the top in Midwestern America before World War II. It was a remarkable achievement, an astonishing debut.

On starts McPherson's second novel, then, with enthusiasm, especially when one sees that at the center of the novel is the same Tommy MacAllister, now a 41-year-old man who insists on being called Andrew, a moderately successful New York playwright, married, with a child of his own, and a new play about to open to great acclaim in London. Several of the most intriguing and attractive characters in Testing the Current are here as well: Daisy Meyer, a vision of erotic loveliness in Andrew's childhood, now a woman in her early fifties living elegantly in London off the wealth of her much older, absent husband; Tommy's widowed mother, a passionate woman whose only hedge against privileged self-indulgence is decorum and repression; and his childhood friend, Michael Aldrich, a streetsmart director of Andrew's plays, a Broadway wiseguy with class.

One needn't have read the first novel in order to enjoy or understand To the Sargasso Sea, but it adds resonance and pleasure if one has because the earlier book limns the later nicely, focuses the themes and gives weight and meaning to the dark moral crisis faced by Andrew MacAllister at what should be his moment in the sun.

To the Sargasso Sea has three main locales -- London, New York and Bermuda. In each place, Andrew contrives for himself a moral conflict that is essentially erotic in nature, a conflict caused by a specific temptation that unexpectedly located in him a forbidden desire that he cannot distinguish from need. The first erotic desire is for an older woman, associated with Andrew's childhood and with his mother, no less; the second is voyeurism; the third is to make love to a man. These desires are not impersonal, of course, nor are they as distinct as this summary makes them seem, for the polt weaves them together, with the various objects of Andnrew's erotic fixations appearing and reappearing in complex, changing -- albeit sometimes improbable -- relations to one another.

The novel opens in London, where Andrew, his wife Ann and 8-year-old daughter Julia have arrived for the opening of Andrew's new play. At the British Museum, he accidentally runs into Daisy Mayer, still as much a vision of loveliness as she was back in Grande Riviere: "Thirty years and more after that summer she seemed scarcely different from the way he remembered her -- the yellow hair, the bright and lively face, the laughter -- except that his memory always included sunlight and the white dress and now she was wearing black and the sun did not light this room." In short order, Adrew finds himself seduced by the blend of memory, fantasy and reality, and in spite of the wise-cracking Michael's warnings, he launches a love affair with Daisy that threatens to sink his carefully balanced and controlled life.

Shaken and guilty, Andrew finally tears himself away from Daisy and returns to New York to attempt writing another play, and, he hopes, to resume his normal life of upper-middle-class domestic bliss. He finds himself profoundly alienated from that life, however, oddly detached from what used to please and amuse him. One afternoon, while idly peering out of his study window through a telescope given to him for his 10th birthday, he discovers that, in the apartment directly across from him, a group of people are making a pornographic movie, and though disgusted, he watches: "Sin enters by the eye," he reminds himself over and over, while he gazes at the complex couplings going on across the way and blends -- as discriminately as with Daisy -- memory, fantasy and reality.

Andrew deals with his third and final temptation in Bermuda, on holiday with Ann, Michael, Sam Walcott, a producer who wants to bring Andrew's play to Broadway, a gaggle of New Yorkers who turn out, by an unlikely coincidence, to be the pornographers from across the street, and David, a young man last seen in London actively trying to seduce Andrew. David is a beautiful, impassioned man who first appeared on the arm of the only critic to pan Andrew's play, and her

he again tempts Andrew to cross the invisible line between conventional bourgeois morality and something other than that, something -- one wants to say "decadent," but McPherson has a more classical turn of mind, so perhaps "Dionysian" would be right.

Andrew swims in the Sargasso Sea, literally and figuratively. It is "a world of marvels and incredible life, fascinating, rich, and strange, hypnoticaly beautiful....He felt magical, transformed." but in that sea he also finds a giant barracuda floating just below him, "an awesome thing, hanging there suspended in its elements. Truly an awesome, terrible thing. He could see its mouth, its teeth."

It various pleasures notwithstanding, To the Sagasso Sea is in many ways a disappointment, a distinct falling-off from Testing the Current. If the resolution to Andrew's conflict seems a little too easily accomplished, it may be because we have been asked to believe that he is not merely sampling alternative models of sexuality but is instead launched on a risky voyage of self-discovery. Moreover, despite moments of brilliance, the book seems arbitrary and contrived, relying heavily on coincidence and happenstance, and all too often, the prose reveals more of the author's desire for effect than the effect itself.

Russell Banks is the author of "Continental Drift" and most recently, "Success Stories." He teaches in the wrting program at Princeton University.