In 2008, Xia Ye receives a mysterious package from the Post Office of the Future, a quiet bundle that contains audio cassettes from the late 1990s and an old cassette player. She tucks the device away for a long train ride to Qingdao, and as the wheels hum along, she presses play and hears the voice of the 17-year-old Ke Da speaking from years past. The tapes carry a charge of memory, offering a window into a summer romance that once felt urgent and present, even as time drifted them apart.
The narrative shifts back to the hot days of 1997, when Ke Da had fallen for Xia Ye during their senior year of high school. Their budding affection found a unique outlet through these very audio messages, a private exchange that bridged distance and doubt. Into this story steps Li Fusheng, a swimmer they met at the local swimming classes, who now runs the Post Office for the Future. He handles messages for the living or the dead to be delivered at some future moment and clings to a belief about the dead: they live on at the Centre of the World, where love keeps reunions possible across the boundary of life and loss.
Arriving in Qingdao, Xia Ye enters a city that has reoriented its own past around the Post Office for the Future, now under the care of Sun Jiaolian. Sun shares a revelation about the Xia Ye who once loved [Ke Da]: she was hospitalized and eventually died of leukemia. This revelation casts a new light on the tapes, suggesting that the recordings were never mere nostalgia but a thread tying two lives across a long span of years.
Meanwhile, Ke Da has traveled down to Qingdao as well, listening intently to the same old cassettes that came into their hands. The ache of heartbreak lingers for him, and he continues to dream of a chance to be with Xia Ye again, a wish that feels both stubborn and intimate as the mystery behind the tapes begins to unfold.
Ultimately, the pieces come together, revealing why these old recordings found their way to both of them. The story resolves not with a dramatic twist but with a quiet, persistent sense that memories, love, and the rhythms of time can connect people in ways that still feel true—even across years and distance.
