This directed case study tells the story of a geriatric patient who has recently been diagnosed with idiopathic pulmonary fibrosis. It begins with him informing his granddaughter, “Jillian,” of the diagnosis. Jillian is a nursing student who is able to answer many questions for her grandfather about what is happening in his body. Acting as Jillian, students will walk the grandfather through an explanation of his disease including changes in lung structure and how these changes will affect gas exchange at the respiratory membrane (and therefore pO2 and pCO2 levels in the blood), leading to eventual acidosis. The case study allows students to synthesize many of the respiratory system learning objectives taught in a college-level introductory level anatomy and physiology class, with a focus on the bicarbonate buffer system and its role in maintaining acid-base balance in the blood. The case could also be used in nursing or other professional programs, or in high school honors or AP anatomy and physiology courses.