The book begins by establishing the historical and religious context of the Jonah story. It then progresses into a detailed exploration of potential candidate fish species, such as whales and whale sharks, before assessing the human body's tolerance to stressors like lack of oxygen and digestive acids. Fish Swallows Man synthesizes biological data to present possible survival scenarios and their associated probabilities, offering a unique perspective for those interested in science, religion, and the intersection of faith and reason.