Yun Shuyue dies suddenly from overwork and transmigrates into the crown princess she drew herself, a villainess who poisons the crown prince on their wedding night. Drinking the poisoned wine triggers a Heart-Linked Gu: whenever the crown prince is hurt, she feels twice the pain; if he dies, she dies instantly, but if she dies, he remains unharmed. To stay alive, she is forced to protect her husband, blocking arrows, heading to the battlefield, and wrapping herself in soft silk, all while the suspicious crown prince mistakes her actions for deep devotion. Lu Xingyao repeatedly plots with poison, only to have her schemes foiled, while Prince Yu attempts to assassinate the crown prince. The truth comes to light during a dangerous autumn hunt, but misunderstandings continue to pull the couple in opposite directions. During a palace coup, Yun Shuyue is captured as a hostage and knocks Prince Yu unconscious with a frying pan before fighting alongside the crown prince. Xiao Jingchuan develops an antidote, but when the emperor personally leads a campaign and is surrounded, Yun Shuyue uses firearms to defeat the enemy and kills Prince Yu herself. After ascending the throne, the crown prince makes her his sole empress. Having survived life-and-death trials together, they finally choose each other wholeheartedly.