So there's this girl named Sylvia, who lives with her grandmother and her surly cow in the New England countryside.
One day, Sylvia meets a hunter, who promptly asks her for a place to stay for the night. He tells Sylvia and her grandmother that he's looking for a rare white heron and is willing to give ten dollars to anyone who could lead him to it. That's big money way back in the day.
And guess what? Sylvia has seen the heron before. So the following night, she sneaks to the tallest tree in the forest to get a good vantage point on the bird. She sees the bird, and then hurries home to tell the hunter what she saw.
When she gets there, however, she can't speak and the hunter leaves disappointed. Although Sylvia holds her tongue for the sake of the bird, she never is sure that she made the right decision.