And nodded in satisfaction. When they were found-as they soon would be-everyone would surmise that they’d jumped from the bridge together and drifted downstream until the piling caught them. The letter sealed in the watertight case would con-firm that impression. He watched to make sure the rope was secure. Then he untied his boat and began the long, cold journey back upstream.

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.