Riding on a mammoth might be fun if you were not cold and hungry and lost, but where would it take you? You continue walking, your spirits sinking. Just as you feel ready to sit down and cry, you see an opening in the ground. You crawl in on your hands and knees. It might provide some warmth, and it might lead to the Cave of Time.

You find yourself in a tunnel. There are other tunnels branching off. You feel sure now you are in the Cave of Time. You are eager to take the next tunnel to the surface, but you want to travel a long way forward in time. Maybe you should take a tunnel further on.