The chapter opens with a description of the role of the white blood cell in the body. The white blood cells are responsible for killing foreign invaders, such as parasites and bacteria. The chapter describes how the stomach reacts to food, and how the food is digested by the stomach. When the food enters the stomach, the stomach secretes a gastric acid, which is then passed down to the rest of the body through the blood vessels. The food is then eaten by the body's own cells, which are called phagocytes. When a phagocyte kills a foreign invader, it is called a "phagous phagocyte," or "white blood cell." The chapter ends with the chapter's epigraph: "The gears of destiny are already beginning to turn."