On a snowy night in Chang'an, Su Wan, a former captain of the Special Service Division, escaped from death with a black iron token, breaking the three-year silence after the failure of the "Midnight Project". She reunited with her old friend Shen Yanzhi at the "Drunk with the Light on" tavern, but she was shocked to realize that the plan was revealed to be a scam by the emperor, and that her former fiancé Gu Yanzhi's "turning over to the enemy" also had a hidden agenda.
From Xishi to Zhongnan, Su Wan and his party not only have to avoid the pursuit of the Jinyi Guards and Black Crow Guards, but also solve the dual conspiracy between the court and the Turks. They teamed up with Lin Mo, the former secret service commander who had retired, and Jianghu forces Qingfengzhai and Xuanjimen. They also received secret help from the old ministries of the DPRK and the Central Committee, and gradually approached the truth that the emperor used his birthday party to frame the envoys and provoke the war.
When the birthday banquet turns into a surprise, the evidence of the crime is revealed to the public, and the former emperor falls. He thought the storm had calmed down, but unexpectedly he was rescued by Turkic forces, and the borderland was in crisis again. Su Wan and Gu Yanyan worked together to pursue the murderer, smash the spy network, and ultimately protect the stability of the Tang Dynasty. From the old grudges on the Mobei battlefield to the new situation in the Chang'an court, a group of loyal and courageous people uncovered the conspiracy with their blood and resourcefulness, and propped up the prosperous Chang'an in the turbulent times, making "Midnight Return" a legend about loyalty and justice.
