Once upon a time, there were three Billy Goats Gruff.  They lived in a little valley in the hills.  One day, they saw a beautiful field of sweet green grass on the other side of the valley.  They wanted to go there.The banks of the river were steep.  The Billy Goats wanted to cross the little wooden bridge.A mouse peeped out of a hole in a tree.  "Be careful," he said to the goats.  "A big ugly troll lives under the bridge.  If you try to cross, he will catch you and eat you!"