Life for Sano Ichiro and his wife Reiko is disrupted when their son, Masahiro, is kidnapped from a festival. After months of searching for him, Sano is told by his enemy and second in command to the Shogun, Tokugawa Tsunayoshi, that his son has been taken to Ezogashima, whose Lord has fallen out of contact with the capital. Lord Matsudaira gets Sano to agree to go north and investigate the situation, as it is possible that the local peoples, the Ezo, are once again in revolt.
Sano's wife, Reiko, distraught over Masahiro's kidnapping, goes with him, as does Hirata, who has been taking time off to do martial arts training, but says he can hear Sano calling him. When they get to Ezogashima, their ship is wrecked in a storm, and they meet the native peoples, called "Ezo" or barbarians by the Japanese. The Ezo, after some pleading, take them in and feed them, then give them beds for the night. But the leader says there will be trouble, but will not elaborate.
The next day, they go to Ezogashima, only to be imprisoned by its lord, Lord Matsumae. He is incensed that someone killed his favorite concubine, Tekare, and now her spirit has inhabited him, driving him mad. He threatens to kill Sano so that the tales cannot get back to the Shogun, but Sano bargains to find Tekare's killer so that her spirit can go free, and so that he can find his son. He questions Lord Matsumae about his son, but Matsumae is evasive.
Meanwhile, Reiko is taken to Matsumae's wife, who she questions about her son, but Lady Matsumae claims to know nothing. When Reiko saves an Ezo concubine from the wrath of Lady Matsumae, she also gains a friend, who tells her where her son is imprisoned. Unfortunately the tower is heavily guarded, and Reiko cannot think of how to break in.
Sano begins his investigation, where he finds out that Tekare was a woman who was a user. Taken from her home by a gold merchant, she moved on to Lord Matsumae, who gave her everything, and even valued her over his wife. She used to call herself Empress of the Land of Snow, but she made enemies due to her high position, enemies who would be only too glad to see her dead. The question is, who among them actually did the deed? Sano must find out before Lord Matsumae has him put to death, and still keep a lookout for his son.
This book contained two interesting elementsin the story, including one that I am not sure I have read before in the Sano Ichiro books. In this case, the supernatural power of the dead concubine, Tekare, is real, and her actual spirit actually *is* in the Lord's body, so she is not just an artifact of his madness. That was very unusual for me to read.
The second thing was something cultural that made me want to gag. At one point in the novel, Sano and Reiko think their son is dead, so they decide to throw their lives away in pursuit of the killer, completely forgetting that they have a 1 year old daughter still waiting for them at home. While the characters may have forgotten about her, I sure didn't!
That being said, "The Snow Empress" is an intriguing mystery that occasionally veers too far into supernaturalism, especially at the end. For most of the book, you can think that Lord Matsumae's madness is simply that, and not actual possession by the spirit of a slain woman. The mystery hinges on secrets and hidden feelings on both sides, that of the Ezo/Ainu and that of the Japanese.
The mystery is well plotted, and with many twists and turns that keep the story fresh and interesting. If you're looking for an interesting, well-plotted mystery to keep you turning the pages, this will put you ahead of the curve.