In Shamus Award-winning mystery author's I.J. Parker's previous work, "Island of Exiles," Heian Period (794-1185) official Sugawara Akitada embarked on a harrowing undercover investigation of a suspicious death on Sado Island. Assuming the guise of a convict, the scholarly Akitada soon found himself in dire straits, and was rescued from almost certain death by a fellow convict named Haseo, who was fatally injured without ever revealing his full name or family background.
Now back in Kyoto, Akitada has settled down to a mundane life as a bureaucrat, in an office with an overbearing superior and scheming subordinate. Things might have muddled along indefinitely if not for two key developments: Akitada's trusted lieutenant, Tora, is detained on suspicion of murdering a blind female street singer; and Kyoto is fast emptying out, as anyone with the means to leave is fleeing a devastating smallpox epidemic. This gives the story a noir quality reminiscent of Robert van Gulik's 1965 Judge Dee mystery "The Willow Pattern," set in Tang Dynasty China's capital during an epidemic.
Between these predicaments and a serious spat with his wife, Akitada tenaciously tries to piece together information about the man who died while saving his life in Sado. Starting from nothing but the deceased's first name, Akitada badgers officials and pores over old records to reconstruct Haseo's identity (a man of noble breeding) and the circumstances of his exile to Sado (for allegedly murdering his parents).