Content Warning: This section discusses a pandemic and death. The source text includes ableist and racist language, which this guide reproduces only in quotations. 

Though the novella’s central conflict pits humanity against nature, it is not much of a conflict. Rather, London presents human beings as quickly and entirely overwhelmed by the Scarlet Plague, which thwarted human effort and will while facilitating societal collapse. That some people live on merely underscores nature’s power, as their survival itself hinges on natural processes. 

London emphasizes the extent of nature’s power by depicting the plague’s impact on a modern industrialized society and, more specifically, on the most privileged members of that society. As a professor, Smith led a life insulated from hardship, but this changed with the arrival of the plague. Smith, and society as a whole, were plunged into a desperate struggle for survival, but attempts to avert disaster proved no match for nature’s raw power. Human beings were helpless in the face of the plague; the boarders at UC Berkeley quarantined themselves but ultimately could not remain uncontaminated, and even scientists were unable to keep up with the disease’s progress. 

The plague ended up destroying the entire human race except for a small band of survivors, whose survival is attributed to inherent immunity.