Explore the human body—more intricate than any machine—and learn how each organ is structured and how it functions in the series. In this third installment, following Book 1's digestive system and Book 2's circulatory system, we journey into the most mysterious organ of all: the brain. Discover the structure and function of the brain's hundred billion neurons, and learn how our bodies operate through the brain, answering all your curious questions about the brain and nervous system. After repeated failed escape attempts, Geo and Dr. Brain finally end up venturing deep into Pippi's brain. But their joy and excitement at reaching the body's command center is short-lived—Dr. Brain discovers something in Pippi's brain that leaves him utterly shocked. Meanwhile, Kay, now certain that Hippo is still inside the body, decides to bring in state-of-the-art medical equipment to draw Hippo out... Chapter 1: Dr. Brain's Mistake Chapter 2: Commander of Our Body Chapter 3: Regions of the Cerebrum Chapter 4: Attack of the Synapses Chapter 5: Kay's Warning Chapter 6: Escape at Last! Chapter 7: Pippi Collapses Chapter 8: Dr. Brain's Choice Chapter 9: The Neural Highway Chapter 10: Pippi, It's Okay Now!