In an urban setting at the beginning of the twentieth century, Propos, a modest bank clerk, tries to protect his life from illness, infection, and every possible danger. His daily routine is filled with rules of caution that gradually turn into constant fear. When he notices a slight change in his body, his anxiety deepens, while medical books and the words of those around him feed his suspicions. At the heart of the story are human psychological vulnerability, the power of one's own thoughts, and the boundary beyond which caution becomes destructive self-deception.