In her previous life, she was Shen Yuan, an orphan girl who was set up by her own sister and sent to the execution stand by her husband. Before he died, he realized that he was just a cannon fodder supporting character in a sadistic novel - existing to set off the kind and infatuated heroine "Shen Yao". Reborn at the age of fifteen, the decree of engagement has not yet been issued, and the poisoned wine has not yet entered his throat. Shen Yuan smiled: This time, she won't run away from marriage, won't make trouble, and won't fight for favor. There are only three things she has to do: first, fulfill the "deep love" between her sister and the prince with a smile; second, secretly take over the secret guard force left by her father; third, make the couple stand as high as possible - because she remembers that in the ending of the original book, the day when the prince's rebellion failed and everyone was executed was accurate to a certain year and month. All she had to do was wait quietly for that day, and then hand over the last knife with her own hands. However, she had calculated everything, but she failed to calculate that the legendary tyrant of the North, the enemy king whose life she had accidentally saved in her previous life, would come to her in advance in this life and said to her: "I heard that you want to kill the whole family of the prince? Count me in."