It is year twenty-five of the Yuantai Era of the Great Zhou Empire. The renowned Marquis of Jingning, commander of the Beiyan Cavalry, Fu Shen is injured on the battlefield at the northern border. Returning with a broken leg to the capital, Fu Shen learns that the emperor has conferred a marriage for him―with another man. To make matters worse, Fu Shen's spouse is his political the famed Imperial Investigator of the Feilong Guard, Yan Xiaohan. In spite of the political differences that stand between them in court, Fu Shen and Yan Xiaohan gradually start to accept each other's presence in their shared home. Yet as they learn to navigate their new life together, it is the calm before the storm. The mystery behind the attack at the northern border begins to unfold, unveiling dangers that threaten the peace of Great Zhou.

As the bond between Fu Shen and Yan Xiaohan deepens, the looming threat above the empire of Great Zhou remains omnipresent. After the settlement of the Kuangshan Academy case, Yan Xiaohan accompanies Prince Qi southward to Jingchu. However, an unexpected storm traps Prince Qi's party inside a mysterious temple and leads Yan Xiaohan into a hidden lion's den. Meanwhile, the investigation on Fu Shen's injury continues to reveal deeper mysteries that enshroud the imperial court. To protect their loved ones and establish peace in this turbulent land, Fu Shen and Yan Xiaohan must conquer the impending danger and uncover the truths of the nation.