This article is a case study and rhetorical analysis of a specific scientific paper on a computer simulation in astrophysics, an advanced and often highly theoretical science. Findings reveal that rhetorical decisions play as important a role in creating a convincing simulation as does sound evidence. Rhetorical analysis was used to interpret the data gathered in this case study. Rhetorical analysis calls for close reading of primary materials to identify classical rhetorical figures and devices of argumentation and explain how these devices factor in the production of scientific knowledge. This article describes how abduction, dilemma, compensatio, aetiologia, and other tactics of argumentation are necessary in creating the simulation of a supernova. Ultimately, the article argues that rhetorical mechanisms may be responsible for making some simulations better and more sound than others.