Four first-grade middle school students in the same class are members of a photography club. Before leaving for summer break, the teacher hands out an old-fashioned analog camera to each of them and asks them to take pictures with them as a summer assignment. The assignment topic is the "end of the world." What does the end of the world mean? What on earth are they supposed to take pictures of? They all have different opinions on it, but as one of the girls suggests, they decide to take a subway to Sinchang Station, the last station on Seoul Metropolitan Subway Line 1. That is the end of the world for these girls. They doze off on the subway, stop for a while due to rain showers, and feel drawn to an unfamiliar world.