Empress

McCune's historical novel about Wu Jao, the only empress to rule China, is set in the seventh century at the height of the great Tang Dynasty. It begins promisingly, with richly drawn scenes of 13-year-old Jao leaving home in a caravan, waiting out a blizzard in a cave and finally entering the capital city of Changan to be tsairen , or concubine, to the Emperor Taitsung. The novel is sharpest in the opening chapters, which detail a tense palace life replete with murderous intrigue that foreshadows the political convolutions to follow. And despite such bodice-busting lines as ``Come, my untamed one. It is time,'' when Jao is finally ushered into the emperor's bedroom, McCune's character is animated enough to keep such soapiness from clogging her swift and steady narrative. With the emperor's death, Jao leaves for a convent only to be recalled by the new emperor, Kaotsung. She becomes his empress, and the novel enters a long, repetitious domestic phase in which Jao and her less-than-executive husband work as a team to defeat one enemy after another. Jao is more interesting as a solo act, which she is again after Kaotsung's death, when she herself becomes emperor. Although the novel has by then become windy, with too many characters being executed and wrongs being righted with a curious lack of drama, Jao carries the book, from age 13 to her 70s, with admirable continuity. (Aug.)