Billy sat under the tree. He was jealous of the birds that were chirping above him and wished he could fly too. Suddenly, he saw something shiny on the ground - it was a nail! He quickly picked it up and started to hide it away in his pocket. Billy turned to see his big sister coming. She had a funny look on her face and asked Billy what he was doing. Billy tried to hide his nail and told her nothing. Heaving a sigh, his big sister told him, "That nail can be very useful if you use it the right way. But it's also sharp, so be careful." Billy was intrigued, but before she could finish her sentence, his sister had run off. He tucked the nail away in his pocket and couldn't wait to find out what his sister meant. The next day, his sister took him to the park where he saw something he'd never seen before - a tree house! She told him that with the nail he found, they could put it together and make it their very own! Billy was overjoyed, and thankful to his sister for taking the time to show him what he could do with the simple nail. He was no longer jealous of the birds - he could now fly too!