Yoriki Sano Ichirō, Edo’s newest senior police commander, made his way slowly on horseback across Nihonbashi Bridge. Early on this sunny, clear winter morning, throngs of people streamed around him: porters carrying baskets of vegetables to and from market; water vendors with buckets suspended from poles on their shoulders; shoppers and tradesmen bent low under the packages on their backs. The planks thundered with the steps of wood-soled feet; the air was bright with shouts, laughter, and chatter. Even the hallmarks of Sano’s samurai status couldn’t speed his passage. His mount, a bay mare, merely raised him above the bobbing heads. The two swords he wore-one a long, curved saber, the other a shorter dirk elicited no more than an occasional mumbled “A thousand pardons, honorable master.”

But Sano enjoyed his leisurely progress, and his freedom. He’d escaped from the tedium that had marked his first month as a yoriki . A former tutor and history scholar, he’d quickly found the administration of his small section of the police department far less satisfying than teaching young boys and studying ancient texts. He missed his old profession; the thought of never again chasing down a lost or obscure fact left a sad, empty ache at the center of his spirit. Still, although family circumstances and connections, rather than choice or talent, had thrown him into the unfamiliar world of law enforcement, he’d sworn to make the best of the situation.

Today he had decided to explore his new domain more fully than he could by sitting in his office and affixing his seal to his staff’s reports. Exhilarated, he peered over the bridge’s railings at the panorama of Edo.

The wide canal, lined with whitewashed warehouses, was jammed with barges and fishing boats. Smoke from countless charcoal braziers and stoves formed a haze over the low tiled and thatched rooftops that extended over the plain in all directions. Through it he could see Edo Castle perched on its hill at the end of the canal. There Ieyasu, first of the Tokugawa shoguns, had established the seat of his military dictatorship seventy-four years ago, fifteen years after defeating his rival warlords in the Battle of Sekigahara. The upturned eaves of the keep’s many roofs made it look like a pyramid of white birds ready to take flight: a fitting symbol of the peace that had followed that battle, the longest peace Japan had known in five centuries. Beyond the castle, the western hills were a soft shadow, only slightly less blue than the sky. Mount Fuji ’s distant snow-capped cone rose above them. Temple bells tolled faintly, adding to the panoply of sounds.

At the foot of the bridge, Sano passed the noisy, malodorous fish market. He edged his horse through the narrow winding streets of Nihonbashi, the peasants’ and merchants’ quarter named after the bridge. In the open wooden storefronts of one street, sake sellers bartered with their customers. Around the next corner, men labored over steaming vats in a row of dyers’ shops. Mud and refuse squished under the horses’ hooves and pedestrians’ shoes. Sano turned another corner.

And emerged into a vast open space where last night’s fire had leveled three entire blocks. The charred remains of perhaps fifty houses-ash, blackened rafters and beams, soaked debris, fallen roof tiles-littered the ground. The bitter smell of burnt cypress wood hung in the air. Forlorn residents picked their way through the mess, hunting for salvageable items.

“Aiiya ,” an old woman keened. “My home, all my things, gone! Oh, what will I do?” Others took up her cry.

Sano sighed and shook his head. Thirty-two years ago-two years before his birth-the Great Fire had destroyed most of the city and taken a hundred thousand lives. And still the “blossoms of Edo,” as the fires were known, bloomed almost every week among the wooden buildings where a strong wind could quickly fan a single spark into a ferocious blaze. From their rickety wooden towers high above the rooftops, the firewatchers rang bells at the first sight of a flame. Edo ’s citizens slept uneasily, listening for the alarm. Most fires were accidents, caused by innocent mistakes such as a lamp placed too near a paper screen, but arson wasn’t uncommon.

He’d come to learn whether this fire had resulted from arson. But one look at the ruins told him he could not expect to find evidence. He would have to rely on witnesses’ stories. Dismounting, he approached a man who was dragging an iron chest from the rubble.

“Did you see the fire start?” he called.

He never heard the answer. Just then, running footsteps and cries of “Stop, stop!” sounded behind him. Sano turned. A thin man dressed in rags streaked past, panting and sobbing. A pack of ruffians brandishing clubs stampeded after him. The man’s bare feet slipped in the mud, and he went sprawling about ten paces from Sano. Immediately the pursuers set upon their quarry, clubs flailing.

“You’ll die for this, you miserable animal!” one of them shouted.

The ragged man’s sobs turned to screams of pain and terror as he threw up his arms to shield his head from the blows.

Sano hurried over and grabbed the arm of one of the attackers.

“Stop, you’ll kill him! What do you think you’re doing?”

“Who’s asking?”

At the sound of the gruff voice beside him, Sano turned. A burly man with small, mean eyes stood at his elbow. He wore a short kimono over cotton leggings; his cropped hair and the single short sword fastened at the waist of his gray cloak marked him as a samurai of low rank. Then Sano caught sight of the object in the man’s right hand, a strong steel wand with two curved prongs above the hilt for catching the blade of an attacker’s sword. It was a jitte , a parrying weapon, standard equipment of the doshin , the law enforcement officers who patrolled the city and maintained order.

Comprehension flashed through Sano. This man was one of his hundred-odd subordinates, one of the long line of bowed heads he’d passed during the formal ceremony at which his staff was presented to him. The armed ruffians, who had ceased torturing their victim to look at him, were the doshin ’s civilian assistants. Privately employed by their superior-and responsible only to him-they performed the dirty work of policing, such as capturing criminals, under his direction. Now three of them moved menacingly in on Sano.

“Who are you?” the doshin demanded again.

Sano said, “I am Yoriki Sano Ichirō. Now explain to me why your men are beating this citizen.”

Although he kept his voice calm and stern, his heartbeat quickened. He’d had little chance to exercise his new authority.

The doshin ’s mouth gaped. He passed a hand over his jutting jaw in obvious confusion. Then he bowed obsequiously.

“Yoriki Sano-san ,” he muttered. “Didn’t recognize you.”

He jerked his head at his assistants, who formed a hasty line and bowed, hands on their knees. “My sincerest apologies.”

His sullen tone belied the respectful words. Sano could sense the doshin ’s veiled contempt. The mean little eyes narrowed still more as they traveled over his freshly shaved crown and his oiled hair drawn into a neat looped knot at the back. They registered disgust at the sight of Sano’s best outer garment, the black-and-brown-striped haori , and his new black hakama , the wide trousers he wore beneath it. Sano bristled at such open rudeness, but he could understand the man’s contempt. The reputation of yoriki for vanity was well known. He himself cared little for fashion, but his superior, Magistrate Ogyu, had stressed the importance of proper dress and appearance.

“Your apologies are accepted,” Sano said, deciding to address the matter at hand instead of making an issue over his subordinate’s manners. “Now answer my question: what has this man done for which you must punish him?”

Now Sano could see bewilderment on the doshin ’s face. Yoriki seldom ventured into the streets, preferring to keep their distance from the rough-and-tumble of everyday police work. They appeared only for very serious incidents, and then as field commanders dressed in full armor with helmet and lance. Sano supposed he was the first to ever investigate a common fire.

“He did this,” the doshin answered, gesturing at the ruins. “Set the fire. Killed fifteen people.” He spat at the man, who still lay facedown in the mud, shoulders trembling with muffled sobs.

“How do you know?”

The doshin ’s prominent jaw thrust out even further, in anger and resentment. “The townspeople saw a man fleeing the street just after the fire started, Yoriki Sano-san . And he confessed.”

Sano walked past the assistants and over to the fallen man. “It’s all right,” he said gently. “Get up now.”

Clumsily the man hunched at the waist, then rose to his knees. Sitting back on his heels, he wiped the mud from his face. Then, to Sano’s surprise, his mouth opened in a wide, toothless smile.

“Yes, master.” His head bobbed, and his eyes twinkled. Despite the wrinkles that creased his cheeks and forehead, he looked as innocent as a child.

“What’s your name?” Sano asked.

“Yes, master.”

Sano repeated the question. Getting the same response, he tried another. “Where do you live?”

“Yes, master.”

“Did you start the fire?” Sano asked, beginning to understand.

“Yes, master, yes master!” Then, seeing Sano’s frown, the man lost his smile. He got to his feet, but fell back as the doshin ’s assistants surrounded him again. “No hurt, master!” he pleaded.

“No one will harm you.” Furious, Sano turned to the doshin . “This man is a simpleton. He doesn’t understand you, or what he’s saying. You cannot accept his confession.”

The doshin ’s face flushed, and he squared his shoulders. The jitte shook in his clenched fist. “I asked him if he started the fire. He said yes. How was I to know he was an idiot?”

A voice from the swelling crowd of spectators cried, “If you’d taken the time to talk to him, you would have found out!” Someone else shouted, “He’s just a harmless old beggar!” Mutters of agreement followed.

“Shut up!” The doshin turned on the crowd, and the mutters faded. Then he faced Sano. “Arson is a serious crime,” he said with exaggerated patience and not a little self-righteousness. “Someone must pay.”

For a moment, Sano was too appalled to speak. This law officer-and many others, if the rumors he’d heard were correct-cared more about finding a scapegoat than about uncovering the truth. He wanted to chastise the man for shirking his duty. Then he saw the doshin s free hand stray toward the short sword. He knew that only his rank kept the man from challenging him on the spot. He’d made the doshin lose face before the assistants and the townspeople. And, on his first day in the field, he had made an enemy.