Luo Yan foresees that an extreme cold wave will lock down the city in seven days. He sells his street-facing ground-floor shop to his greedy aunt, Wei Chunfang, and moves into a rooftop duplex with his mother, Zhang Guilan, and younger sister, Luo Xiaoman. Together with his good friend Fang Xiao and Qin Li, the manager of a courier station, he stockpiles food, seals the windows, and reinforces the doors. When the cold wave strikes, the water pipes in the ground-floor shop burst and freeze over. Wei Chunfang and Luo Yan's ex-girlfriend, Tang Yue, repeatedly gather groups of people to steal their food, but Luo Yan drives them away with ingenious tactics involving pepper spray, flour explosions, flaming fuel barricades, and lightning strikes. He drills through the ice to catch fish and builds an underground food cellar. Against all odds, Luo Yan protects his home and leads his family and friends through the freezing winter of the citywide lockdown.