Zhan Shuo, commander of the Imperial Brocade Guard, and Xie Lanyin, daughter of the Grand Tutor, become connected through a kidnapping case and are betrothed by imperial decree from the Empress Dowager. From mutual suspicion and cautious probing to standing united side by side, they join forces to navigate court intrigues and struggles over the imperial succession. Along the way, they gradually uncover the truth behind the tragic massacre at Luoying Ravine ten years ago and the suffering of Zhan Shuo's biological younger sister. In the end, they overthrow the tyrannical emperor, help the new emperor ascend the throne, restore the good names of the fallen loyal souls, and uphold their promise to remain devoted to each other for a lifetime.