In her works of nonfiction, Marina Warner has demonstrated her extensive knowledge of two subjects: Chinese history in The Dragon Empress: The Life and Times of Tz'u-hsi, Empress Dowager of China, and the Catholic Church in Alone of All Her Sex: The Myth and Cult of the Virgin Mary. But Knowledge doth not a novel make, and Warner's first fictional work, which incorporates these two subjects, is not wholly successful.

In a Dark Wood is the story of the simultaneous misfortunes that befall two aging brothers, Englishmen raised in China and now living in London both having risen to important positions in their respective professions. Jerome Namier edits a prestigious literary periodical until it is revealed that the Review has been accepting money from an organization that is a front for the CIA, a situation in which Jerome was deceived by his best friend. His elder brother Gabriel, of whom he has always been intensely jealous, is a highly respected Jesuit priest and scholar. The arrogant and seemingly emotionless Gabriel is involved in editing the diaries of Andrew da Rocha S. J., one of a group of Jesuits who tried to convert China in the 17th century. As Gabriel delves into da Rocha's diaries, he becomes obsessed with the man's attraction to Chinese thought, a mirror of his own discovery that he has fallen in love with a young man.

Although the decline and fall of the Namier's brothers has the markings of an interesting story, the novel is flawed in a number of ways. Jerome and Gabriel remain curiously undeveloped, too unrealized to generate much interest or sympathy in the reader, and the end of the novel seems too neat and tidy. Much of this is due to the fact that the novel is too short to accommodate all that its author has tried to include in it - the stories of both brothers, the large amount of material that purports to be from da Roche's diaries, and the stories of the other members of the Zamier family, all of which contains seeds of interest but finally seem irrelevant and unnecessary. As the omniscient author jumps from the mind of one character to another, the reader is simply overwhelmed by the effort of keeping up.

Finally, In a Dark Wood is marred by such overwritten prose as this: "The lines outside the house were tasselled with tight buds that held the promise of summer's scent, and Paula felt a creamy contentment inside her rise in anticipation." Enough to make one glad that Warner is returning to nonfiction in her next book, a biography of Joan of Arc; in that unhappy story, at least, perhaps we will be spared any rsing of "creamy contentment." (Knopf, $8.95)

- Susan Wood.