In a small town, twelve mysterious letters and a 35-year wait intertwine to shape the lives and loves of close-knit friends and family. Tang Yixuan’s world is thrown into turmoil when his beloved vanishes, followed by cryptic messages arriving from another time. Driven to uncover the truth, he plunges into a complex puzzle, navigating dual timelines and unraveling the secrets hidden within the letters that could explain her disappearance.