THE IRIS FAN, by Laura Joh Rowland. Minotaur. 346 pp. $25.99.
Twenty years ago, Laura Joh Rowland began writing a mystery series about a samurai detective who walks the mean streets of feudal Japan. Through war, pestilence and regime changes, Sano Ichiro -- often aided by his resourceful wife, Reiko -- pursued the truth about crimes committed on his watch, even when his investigations put him in conflict with his code of bushido, or absolute allegiance to the shogun. Certainly to the distress of her fans, Rowland has decided to conclude her series with "The Iris Fan," the 17th Sano Ichiro novel.
Most mystery series tend to end with a whimper because their creators have run out of gas or died in medias res. Rowland, in contrast, has granted her samurai the honor of going out with a bang. The chaos commences in a prologue set in the dead of a winter's night in the shogun's palace. The aged shogun, his body weakened by an attack of measles, lies sound asleep beside his reluctant bedmate, a beautiful adolescent boy. Into the chamber creeps a black-robed figure wielding a fan. "This was no ordinary fan used to create cooling breezes in summer. It was a weapon of the kind used for self-defense, often by merchants, peasants, or women." Sure enough, the unthinkable happens: The mysterious intruder plunges that fan into the shogun's back and flees.
Meanwhile, Sano is having a pretty miserable night himself. Sleet is falling as he and his loyal sidekick ride on horseback toward the "pleasure quarter" of Edo (the ancient name for Tokyo). After four fruitless years of investigation, Sano finally has a lead on the murder of the shogun's appointed heir, Yoshisato. Sano is convinced that the suspicious fire that killed Yoshisato was set at the orders of Lord Ienobu, the sworn enemy of Yoshisato's father. Sano has paid a terrible personal price for his relentless investigation of the murder, which has put him in bad favor with the powerful Ienobu:
"In four years he'd been demoted four times, from chamberlain down to patrol guard, the Tokugawa regime's lowest rank. His son Masahiro, aged seventeen, was also a patrol guard, with no prospects for advancement, and their family had been evicted from their estate inside Edo Castle."
Sano and his sidekick, their padded cloaks drenched by freezing rain, finally arrive at the brothel, where, according to an informant, Yoshisato's murderers are enjoying some R & R. Instead of a solution, however, Sano receives a shock. It turns out that Ienobu and the dead heir's father, longtime mortal enemies, are now allies and determined to put a permanent end to Sano and his investigations.
In addition to intricate plotting, Rowland's consistent strength throughout her series has been the authority she brings to her portraits of her idiosyncratic characters and their world. Chief among those characters, of course, is the indefatigable Sano, who has grown older and, thus, more aware of the limits of his physical and even moral endurance. His dual -- and often conflicting -- commitments to the shogun and to the pursuit of justice have brought him, time and again, to the brink of snapping. It's high time that Sano bowed out of the detecting business and reaped the rewards of his dedicated labors.
At the end of "The Iris Fan," we get a faint suggestion that, though this may be Sano's last official case, he just may be available for private consultations. If so, Rowland's many fans -- as well as the beleaguered citizens of feudal Japan -- will be most grateful.