Leon Parker is a little boy who likes to ride his bike after school, and sit under a big tree looking up at the sky. He wishes he could play high up in the clouds. One day Leon gazes up at the clouds and suddenly sees a face. Through the white puffy clouds he sees what looks like a little boy his age Billowy (Billy) McFluff lives up in the sky in Cloudy-Town and just like Leon, wondered about the people on the ground. He always wanted to meet a Below. Billy invites Leon to come up to Cloudy-Town and play together. Leon accepts eagerly and rides up a cloudy stairway on his bicycle to Cloudy-Town. Together they have the adventure of their lives, including a visit with the Snowflake kids of Snowy-Town, and the Raindrop kids of Rainy-Town. But just when things are getting exciting, the angry Gloomy Clouds, Thundering Drummers and Windy Gushes invade their fun and chase away the all the Cloudy-Town and Rainy-Town kids. Leon frantically looks for his bike and the cloudy stairway to get home before the Gloomy Clouds and Thundering Drummers catch up to him