Worst Case Scenario features several characters who find themselves thrown into crisis, and the author uses this premise to examine various ways in which people respond to high-stakes situations. The story therefore conveys multiple definitions of heroism and leadership. Some of these characters—like Joss and Ethan—are trained to handle nuclear accidents and emergencies, while others—like Steve and Dani—are firefighters who deal with more mundane emergencies on a daily basis. Still others are untrained civilians who must find ways to cope however they can, and, notably, the author creates heroes in all three categories as the crisis unfolds, implying that true heroism is not limited to self-sacrifice; instead, it is a multifaceted attribute that manifests in many different ways.

At the plant, Joss and Ethan are thrown into intense leadership roles during the crisis due to their jobs and their training. However, they differ greatly in their approach, and Newman uses their conflict to explore the ethical dilemma of whether to sacrifice the safety of a few for the good of the many. This conflict comes to the fore when they have to decide whether to vent the gas off the spent fuel pool, and it arises yet again when they are forced to send someone into the radioactive water to manually turn on the pump.