Freight-hauling couple Li Mei and Zhou Erqiang bear the heavy pressures of life. Due to losses incurred during watermelon transportation, while driving into an abandoned tunnel, they accidentally time-travel to Pingyang Ferry in the Daqi Dynasty. Facing soldiers and civilians struggling with severe water shortage, the watermelons on the truck resolve their urgent crisis. From then on, the two begin a dual life: running their daily routines normally by day, and driving a semi-truck across time and space at night to transport water, grain, and production supplies. They must deal with the covetous eyes of others while facing border warfare, using a single freight truck to fulfill their original aspiration and protect the people of a city to the best of their ability.