During a team-building activity playing a murder mystery game, Yang Ling unexpectedly travels to a world called Dafeng, taking on the identity of a constable at the Changle County Yamen—Xu Qi An.

Xu Qi An decides to remain in this world and live well. His first goal is to make money.

Xu Qi An dreams of becoming a Night Guardian. But after solving the case, he is forced to go through report after report every day at the yamen. It's torturing.

While Xu Qi An is being escorted, Xu Ping Zhi attempts a rescue but is outnumbered. He ends up being imprisoned in the Ministry of Justice’s dungeon together with Xu Qi An.

Xu Qi An uses 20 Exhortation to Learning poems to convince Scholar Zhang Shen and Li Mu Bai to let his female family members stay in the academy. When Huai Qing sees his "Exhortation of Learning" poem collection, he is secretly impressed.

Xu Qi'An learns about the grudge between Zhou Li and Zhang Yun Ying, Marquis Weiwu's illegitimate son, from Fu Xiang.

Xu Qi'An agrees to join the Night Guardians. He becomes a Copper Guardian officially.

On his first day on duty, Xu Qi'An eagerly learns about the daily duties of a Night Guardian, ready to jump into action. However, he is assigned to stay behind closed doors and review case files instead.

Xu Qi'An finds out that someone is mining saltpeter that can be made into gunpowder. He wants to return to the capital city to report it. But he is attacked by a beast from the Kui Tribe. Chu Cai Wei, Song Ting Feng, and Zhu Guang Xiao can't defeat the beast even when they combine forces.

Lin An discovers that Xu Qi An has mistaken her for Huai Qing. To obtain his poems, she decides to impersonate Huai Qing.

Xu Qi'An reports to Wei Yuan about the Jade Mirror incident. Wei Yuan orders Yang Yan to head to the rendezvous.

Xu Qi'An thinks that the Princess Royal is responsible for the benefits that he's getting from the Night Guardians. When Lin An finds out, she admits that it's her doing.

Jiang Lv Zhong, Nangong Qian Rou, and Yang Yan have a disagreement and take it to the training grounds for a fight. Xu Qi An, ever curious, rushes over to watch the spectacle, only to discover that he himself is the cause of the conflict.

A ceremony is held at Sangbo Lake. As Xu Qi An is guarding over the area, the Jade Mirror suddenly emits a sound.

Xu Qi An and the rest are beaten up in public by the Silver Guardian leader, Zhu Cheng Zhu. Xu Qi An endures every difficult moment and humiliation thrown at him by Zhu Cheng Zhu.

Huai Qing sends someone to find out more about the attack on the Silver Guardian. What she finds increases her admiration and respect for Xu Qi An.

Xu Qi An and the Night Guardians investigate Sangbo Lake. They find a formation underwater...

Wei Yuan takes Xu Qi An to the palace. He wants him to find Princess Royal to proceed with the investigation. Huai Qing's personal eunuch comes to lead the way. He asks him about his relationship with Princess Lin An...

Huai Qing tells Xu Qi An the story of Princess Ping Yang, who has fled her arranged marriage and run away from home. Meanwhile, Lin An is frustrated over how Xu Qi An has chosen to serve Huai Qing instead.

Xu Qi An reports to Wei Yuan that the clues he discovers are pointing towards Qinglong Hall. Tiandi Society's No. 6, Heng Yuan is also missing.

Yang Qian Huan teams up with four Gold Guardians to fend off Heng Hui. Heng Hui is devoured by the demonic arm. He escapes after receiving a devastating blow. Yang Qian Huan knows that Xu Qi An, the main investigator of the case, is quite capable. He thinks of him as a formidable foe.

Officials of the imperial court are fighting for the position of Minister of War. Wei Yuan gives up on the opportunity and asks for Xu Qi An to be spared.

Xu Qi An encourages Lin An to pursue her freedom, and it motivates her.

The news of Xu Qi An's sacrifice on the battlefield reaches the capital, and the officials turns down the request to honor him with a posthumous title.

Xu Qi An analyzes Shen Shu's origin and realizes that he has been caught in a conspiracy.

Wei Yuan reports the rumor of a 3,000-li massacre. Emperor Yuanjing is shocked and alarmed.

Xu Xin Nian and Xu Qi An arrive at the designated location to meet Wang Si Mu. Wang Si Mu agrees to Xu Qi An's request to enter the Ministry of Personnel.

Wei Yuan gives Xu Qi An the confidential letters containing evidence of corruption and malpractice committed by Duke Cao and other unaffiliated officials. If the Wang faction presents them to the Emperor, it could help Wang Zhen Wen overcome his crisis.

Xu Qi An and Su Su enter the Ministry of Personnel to look at the files. He finds a blank space in the file where the name should be. Xu Qi An realizes that there is an unimaginable force at work.

Nangong Qian Rou finds Xu Qi An. She tells him that His Majesty had ordered him to engage the dharma statue as Dafeng's representative. Xu Qi An worries that the Imperial Astronomer has found out about Shen Shu, who's inside his body at the moment.

The battle begins. Everyone is here to witness this battle with the Celestial Realm. Xu Qi An dones on his battlesuit and walks out of the Imperial Observatory.

Xu Qi An falls into an illusion. Du Ku shows up and asks Xu Qi An the meaning of his life. He tells him that it's better to live in despair. In return, Xu Qi An asks Du Ku the meaning of his life and it challenges his resolve.

The Emperor appoints Xu Qi An as the chief investigator to travel to Chuzhou and investigate the holocaust case. Xu Qi An uses the jade mirror to contact Li Miao Zhen and asks for her assistance. They travel north together.

Xu Qi An realizes that Mu Nan Zhi is on the ship with them. He predicts that Mu Nan Zhi is a member of Lord of the North's Residence. He also speculates that they will encounter an ambush.

Xu Qi An finds out that the Lord of the North is the real culprit behind the holocaust case from his spy.

Jili Zhigu wages war against Lord of the North, but is knocked to the ground. At this moment, Xu Qi An appears and announces the crimes of Lord of the North to the masses.

Xu Qi An advices Emperor Yuan Jing to uphold justice for the people of Chuzhou by convicting the Lord of the North. But Emperor Yuan Jing asks everyone to leave.

On the court, the imperial relatives try to twist the facts, making it so that Lord of the North is a hero of the state as he sacrificed himself to defend the state. Zheng Xing Huai insists on fighting for justice.

Zheng Xing Huai is executed. When Xu Qi An finds out, he arrives at the palace gate. Wei Yuan advices Xu Qi An that it's not the right time and asks him to go back.

Xu Qi An makes Que Yong Xiu confess that Lord of the North massacred the city. The Imperial Guards arrive at the scene. Tiandi Society and the Night Guardians show up to stop them.