Severe sepsis is the term used to describe the host response to infection when complicated by acute organ dysfunction. Severe sepsis occurs in more than 750 000 individuals in the United States each year, with a hospital mortality of about 30%. Although the classic presentation is of florid shock with frank hypotension, fever, and elevated white blood cell count, many patients can present with cryptogenic shock (shock without hypotension) with more subtle signs of vital organ compromise. Using the case of Ms C, a 47-year-old woman with short gut syndrome and an indwelling intravenous catheter who developed an episode of severe sepsis secondary to a central line infection, treatment of sepsis is discussed. Management consists of prompt intervention with broad-spectrum antibiotics and fluid resuscitation, even in the absence of hypotension, and institution of a variety of strategies in the emergency setting to prevent development or worsening of vital organ dysfunction. Although advances in understanding the host immune response have fueled considerable interest in immunomodulatory therapy, the role of such agents in clinical practice remains limited and controversial.