This interrupted case study tells the story of “Michael Mathers,” a tourist traveling on a cruise ship who suddenly becomes sick. Despite receiving a preliminary diagnosis and treatment by the cruise ship doctor, Mr. Mathers’ symptoms continue to worsen, prompting his return to the ship’s doctor. He then finds out that many other people are experiencing similar symptoms, and surprisingly, they are all male. The overwhelming number of cruise patients prompts an emergency docking and a trip to the hospital by the passengers to discover the cause of the outbreak. In order to arrive at the correct diagnosis of Legionnaires’ disease, students review bacterial morphology, laboratory techniques for identification of microorganisms, viral and bacterial infections, biofilms, and principles of epidemiology. This case was developed for an introductory-level microbiology course for undergraduate non-majors, the majority of whom are on the allied health track, and could be implemented when discussing microorganisms related to the respiratory system.