Lisa sees a volcano that is almost ready to erupt. Marc demonstrates a model volcano. Trini joins a group of young archaeologists uncovering fossils along the Illinois River.ANIMATIONS: The moving rocks of Earth; one billion years of Earth change is compressed into 1¾ minutes.THE BLOODHOUND GANG: ""The Case of the Missing Bloodhound, Part Two."" Mr. Bloodhound has left behind another secret message for the gang, which leads them directly to the kidnappers.