Bill Nye is obssessed with erosion and explains that rocks change over time. He explains what causes weathering (although he calls it erosion): water, ice, wind, sand, and chemicals. He illustrates the process of erosion in his lab.

Sid tells Manny and Diego that the floor is hot. They find out that they're walking on a bed of igneous rock when the volcano erupts. They have a few close calls but all manage to escape to safety.

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.