Fifty bugs have invaded the body! Can the defenders stop them? As the invading bugs move from the skin into the mouth, down the throat into the stomach, and eventually to the brain, they mutate and change. Now the defenders must find creative ways to eliminate the pesky bugs that include a hairdresser, a tooth troop, a digestive tracker, and a lung glider. In this colorfully illustrated book, little ones are guided through an amazing puzzle adventure through the human body as its brave defenders attempt to fight off fifty bugs.