In the future, humans have exhausted all fossil fuels and fully rely on solar power. Energy companies begin to fully control the sun, and human society moves towards Solar Power II civilization. But in an unexplainable astronomical event, the sun suddenly disappears. Introverted astronomical free-lance writer Sun Yang and his useless neighbor Chen Mu are forced to team up together in order to escape this catastrophe, and find the rumored last safe haven, District Four. On their way, they meet numerous people, and witness both the cruelty of humanity and farewells with warmth. After countless encounters with death, the two lonely souls finally grow closer, and begin to understand the meaning of life during a disaster...