The narrator explains how sedimentary rocks form: from sediment deposited in water through the process of weathering and erosion. He also explains the layers of sedimentary rock, which include sandstone, limestone, and conglomerates.

The Polar Express is sliding on the ice, and the crew attempts to get the train back on the tracks before the ice collapses underneath them.

Sabrina explains how the earth changes using seasons and landforms as examples. She illustrates how landforms form and change over time by mentioning plate tectonics, erosion, and weathering. She uses famous examples of gradual change (The Grand Canyon and The Old Man of The Mountain) as well as examples of quick change (Mount St. Helens) to stress that the earth changes in ways that are both noticeable and not so obvious.

Clark and his family head for cover as a huge tornado destroys everything in its path. Jonathan sacrifices himself to save the family dog.

Bill Nye explains why it gets colder as one travels up through the atmosphere. He uses miniature replicas of a city and a mountain to support his explanation. Bill also briefly touches upon the lapse rate.