An informant and his daughter are murdered at the South Market. Gao Bingzhu infiltrates the Dali Temple prison, posing as a suspect to extract information and learns the informants are dead and a grand plot is underway.

Gao Sheng reports to the ruler that Gao Bingzhu, the killer in the South Market case, has surrendered. Si Yue openly points out that the case is full of doubts.

Gao Bingzhu is accused of murdering Chen Que and others. Si Yue and Pei Jian lead a team into the slums to capture him, but Gao Bingzhu willingly reveals himself.

The Dali Temple deems Gao Bingzhu a repeat killer. Gao Sheng orders all exits of the slums sealed. To save the area, Gao Bingzhu negotiates with Pei Jian, promising to find the real culprit within ten days.

Gao Bingzhu exhumes a body and deduces that Baili Yan was poisoned by venom from the Western Regions. Reviewing records, he finds anomalies in copper materials and shares this key clue with Si Yue.

By the Yi River, Gao Bingzhu and Si Yue witness Tiangou’s group swapping copper ore for relocation. Afterwards, the group plans to kill the laborers, but Si Yue rushes into the fire to save them.

Baili Hongyi realizes the marriage alliance between the Baili and Liu families is part of Liu Xiang’s scheme. Drunk, Gao Bingzhu recalls the past and breaks down, with Si Yue staying by his side.

Baili Hongyi uses a return visit with Liu Ran as an excuse to probe Liu Xiang. Meanwhile, Si Yue proposes cooperating with Gao Bingzhu.

Gao Bingzhu sneaks into the Xunshan Duke’s office and obtains the account book, but its coded text can only be read by Liu Xiang’s people. To decipher it in time, Si Yue suggests seeking help from Lianfang.

Gao Bingzhu and Baili Hongyi locate an underground copper workshop but are attacked by craftsmen. Gao Bingzhu manages to escape with Baili Hongyi.

Siyue and Baili Hongyi suspect Gao Bingzhu has gone to the Xunshan Duke’s residence. When they arrive, Liu Xiang has already taken poison and died. They blame Gao Bingzhu for acting recklessly.

Baili Hongyi and Gao Bingzhu discover a hidden weapons workshop beneath the slums. Gao plans to take Baili to meet Wang Dengcheng, but Wang’s strange behavior raises suspicion, so Gao hints that Baili should seek reinforcements.

While pursuing Shiliuye, Gao Bingzhu is intercepted by Li Beiqi, allowing Shiliuye to escape. Gao is captured and taken back as a suspect.

In a ruined mountain temple, Gao Bingzhu finds Wang Dengcheng, his unconscious mother, and Si Yue bound. Wang tries to recruit Gao into Chunqiu Dao, and when he refuses, forces him to choose between his mother and Si Yue.

Si Yue receives an invitation from Princess Changle. The Prince of Jin oversees Song Liang’s case, while the Crown Prince, fearing implication, seeks Si Yue’s help to prove his innocence to the ruler.

Gongzi Chu asks Gao Bingzhu to escort Wang Dengcheng from Dali Temple to Lianfang, but Wang is killed midway by Shiliuye. Baili Hongyi notices Liu Ran secretly following and takes her along to Lian Mountain.

Gao Bingzhu discovers that Ruo’an communicates with informants through coded signals using pottery and food. Reporting this to Gongzi Chu, they expose the spy and decide to root out the traitor within Lianfang.

After returning to the capital, Baili Hongyi arranges to meet an official at Liubai Tower. Shiliuye reports this, and is ordered to learn the details and then eliminate Baili Hongyi.

Si Yue decides to personally watch over Baili Hongyi, with Li Beiqi staying to assist her. Gao Bingzhu compiles a list of suspected traitors and interrogates them one by one, causing discontent within Lianfang.

Si Yue tells Gao Bingzhu that Shiliuye may be a woman. Baili Hongyi causes trouble at the Internal Guard office correcting errors, annoying everyone. Li Beiqi detains him in the guard’s jail.