Cultural relic restorer Lin Xia accidentally traveled through time due to a compass from the Ming Dynasty, and met electrician Chen Mo for the first time in 1985 at the Zhengyangmen Gate Tower. In the rift of time and space that spanned thirty-eight years, the two recognized each other through faded love letters, old-fashioned radios and other tokens, but when they traced their life experiences, they discovered that they were actually ancestors and grandsons. When Lin Xia predicts the outcome of Chen Mo's death, the paradox of time and space and ethical taboos push them into the abyss of choice. As the secret files of the Forbidden City reveal the legend of time and space lovers during the Yongle period, the two started a business in Zhongguancun, passed the Morse code on the Great Wall Beacon Tower, and finally completed the time and space closed loop with the engraving of a wedding ring, a story of eternal love that transcends the cycle of life and death.
