Long-distance freight couple Zhou Erqiang and Li Mei arrived unexpectedly at the resource-scarce Pingyang Crossing due to a mysterious tunnel. A truckload of watermelons established their bond with Gu Changting. Since then, they traveled back and forth between two worlds, bringing drinking water, grain seeds, farming tools, and medical supplies to help local people improve their livelihood and restore production, while also facing severe trials of family, career, and secret guardianship in modern life. Ordinary people built a path of mutual assistance across time and space with diligence, kindness, and wisdom, jointly guarding their home and hope.