Reasoning that you can always find your way back into the cave when you want to, you decide to explore the world in which you have found yourself.

You make your way along a rock ledge overlooking the plains and lakes, taking care to keep your bearings so you can find your way back to the cave.

By now you are getting very hungry. You know that you are in the age of reptiles at least 100 million years ago–and that mammals may not yet have appeared on earth. There will be no rabbits or deer to hunt, though the lakes may contain fish. You wonder how dinosaur eggs taste.

You follow a wide path through the fern trees. When you round the first bend, you find yourself face to face with the horrible Triceratops, a great gray monster almost hidden behind its shields and horns. It looks at you curiously with dull brown eyes. You turn, run, and crash into a tree trunk, one that wasn’t there before!

The bark feels like leather. You look up to see how high it is-into the jaws of Tyrannosaurus Rex.