At the execution ground, the groom Gu Yanzhou, whom Shangguan Susu had been waiting for, personally took the executioner's blade. Believing her childhood sweetheart had broken their old vow, she did not know he had exhausted his remaining lifespan to borrow thirty days with her and return to the human realm. Along the way to clear her father's name, she gradually saw through his guilt and deep affection, while also discovering that with each day she lived, she would forget a bit of the memory of falling in love with him. When the mastermind behind the scenes offered an opportunity for them both to live, the price was taking the lives of the innocent. As the thirty days draw to an end, how will she guard her own life and hold onto the person who is being forgotten?