When Jiang Li, an assistant professor in the Department of Modern History, was restoring ancient books in the Forbidden City, she accidentally touched an ancient jade hairpin engraved with the word "Yan", traveled to an imaginary dynasty, and became the second lady of the Zhenbei Hou Mansion. Her mismatched behavior with her original owner attracted the attention of the cold lord Zhou Yu, who actually had the same appearance as the ancient general who repeatedly appeared in her dreams.
When a plague breaks out in the capital, Jiang Li relies on modern medical skills to join forces with Zhou Yu to fight the epidemic, and the two develop a secret love. Zhou Yu admitted that he was a "rebel" who remembered his past life since he was a child, and had been waiting for her to appear in his dreams. However, there was strife in the court, and the crown prince forced Zhou Yu to marry into the Prime Minister's Palace. On the eve of the wedding, Zhou Yu left half of the jade pendant as an oath, and was immediately sent to fight on the border.
Jiang Li found a way to return to modern times, but chose to stay and help. After their identities were exposed, the two made a private vow in an ancient temple while on the run. Zhou Yu threw himself into a trap to protect her from leaving. Jiang Li took the risk to rob the prison, but learned that the prince had kidnapped the emperor. Zhou Yu would rather die than cause chaos in the world. On the occasion of farewell, Jiang Li died in Zhou Yu's arms, and the jade hairpin flashed with strange light——
Jiang Li suddenly woke up on the modern hospital bed, holding the ancient jade hairpin tightly in her hand. She frantically searched for evidence of Zhou Yu's existence, and finally broke down in tears in front of the portrait of Princess Yan in the Forbidden City: the person in the painting looked exactly like her, and half a jade pendant was quietly displayed in the display cabinet, which perfectly matched the one given to her by Zhou Yu.
**"The exquisite dice is decorated with red beans, and I miss you deeply."** Thousands of years apart, when the sun sets in spring, she can still hear the sound of the piano that travels through time and space.
