On the way back to camp, Jenny and Carlos are caught in a bad storm. They take shelter under a rock, at the entrance to a cave. When they crawl into the dark cave, they get lost. A talking bat promises to lead them out of the cave.

The bat helps Jenny and Carlos find a flashlight. They can see strangely shaped rocks and crystals all around them. A white fish with no eyes swims in an underground stream.

Jenny and Carlos meet more cave animals. White crickets and beetles live on piles of bat droppings. They can't see in the dark. Instead, they use long feelers to find their way.

Dripping water and rock take thousands of uears to form cave sculptures. Sometimes people break the formations and they are gone forever.

People have used caves for centuries. In one cavern, Jenny and Carlos are impressed by paintings drawn by early Ameraicans thousands of years ago. After they see the cave art, the bat leads the children out of the cave and they go back to camp.