The mysteries in I.J. Parker's Sugawara Akitada saga, set in the latter part of Japan's Heian Period (794-1185), are now up to 17 full-length books. Throughout, she has skillfully adopted the literary model of the traditional Asian crime novel in which the protagonist, a "righteous official," must investigate several puzzling cases. A retired professor of literature, Parker was originally drawn to the period via research.