The Lone Blade of Han: Securing the Realm

In the fourth year of Yuanshou of the Western Han Dynasty, in the prison of Chang'an. Lin Feng, deputy captain of the criminal investigation unit, woke up, but he was no longer himself. Iron chains pierced his bones, and he was to be beheaded the next day. The original owner, Guan Fu, grandson of Guan Ying, was sentenced to death for punching Prime Minister Tian Fen. Within three hours, he identified poisoned wine, thwarted a conspiracy, and extracted two life-saving pieces of intelligence from Sima Qian in the neighboring cell—one that could topple Tian Fen, and another about celestial anomalies. He passed the news of the lunar eclipse to the physician Su Wan, who then relayed it to Emperor Wu of Han via Dongfang Shuo. That month, while all of Chang'an was driving away the celestial dog to save the moon, Guan Fu heard two words from above: 'Pardon.' The day he walked out of prison, he thought the nightmare was over. He didn't know that ahead lay the wind and sand of the northern deserts, the lonely city of the Western Regions, the blood calamity of witchcraft, the desperate situation at Mount Junji—and a person he once trusted most, whom he now had to kill with his own hands. The end of a death row prisoner is the beginning of an era. One man's journey is the blade of an era. — Description from novelcodex.org