Just after becoming the director of the Psychoneurotic Institute for the Very, Very Nervous, Dr. Richard H. Thorndyke (Mel Brooks) is greeted by a series of mysterious events. When his colleagues -- including the militaristic and mustachioed Nurse Diesel (Cloris Leachman) -- become leery of his questions, they accuse him of murder. Thorndyke's own mental health comes into question as he struggles to clear his name in the midst of a crippling bout of a condition known as high anxiety.