Twenty-eight-year-old cultural relic restorer Jiang Mucheng met Ye Qing, a twenty-year-old botany girl, at the darkest moment in his life. A dusty lighthouse diary closely connects two people in seemingly parallel worlds. He taught her to read the traces of time, and she showed him the new green of life. This is a companionship that begins with healing, but inadvertently grows into the most irreplaceable warmth and light in each other's lives.