Beakman explains that shoes stink because of the bacteria on your feet. He uses a microscope to quickly show that there are bacteria everywhere and then a short animated clip to show how your feet produce oil and sweat that the bacteria eat. This creates smelly biproducts to make your feet stink. He then does a DIY bacteria growth experiment where he grows bacteria from his sweaty feet in a jar of gelatin.
In an attempt to be scary, Double D dresses up as the bubonic plague for Halloween. Despite his hints, which include facts about the plague, Ed and Eddy are unable to figure out what his costume depicts.
What is plague? How many people died from the Black Death and the other plague pandemics? Learn about the bacterium behind the plague disease, how factors like trade and urbanization caused it to spread to every continent except Antarctica, and how three devastating pandemics helped shape modern medicine.
Ralphie's class enters his body to find out what is making him sick. His classmates find bacteria cells in his throat and watch the white blood cells battle the bacteria cells. This clip illustrates the function of white blood cells: to fight infection and disease.
The group escapes from hepatitis B and enters Alveoli Forest, where they encounter the bronchial tubes, alveoli, and the disease, tuberculosis. Dr. Bloom explains that the human has latent tuberculosis, as the disease is usually found in many people's lungs but is not active. He changes his opinion, however, when he sees that tuberculosis bacteria has escaped from its inactive state.