In this video-centered case study, “Liam” meets with healthcare professionals and is diagnosed with diabetes insipidus due to the loss of vasopressin caused by a head injury. After watching Liam’s story, either at home or in class, students answer a series of questions designed to reinforce and expand their knowledge of physiology with a focus on fluid and blood pressure control. Although the role of Liam is performed by an actor, the scenes were filmed in a working hospital with actual healthcare professionals to pique student interest in a wide range of healthcare professions. Upon completion of this case, students should be able to describe the role of vasopressin in fluid balance and blood pressure control, and to describe the consequences of loss of vasopressin and physiological compensatory mechanisms. The case includes an optional cell and molecular biology extension, and is also available in a clicker-case or multiple-choice format (see Supplemental Materials). It was designed for an introductory physiology course for science majors and could also be used with students in healthcare programs such as nursing and medicine.