It's a rainy day and Caillou is disappointed because he will not be able to go play at the park with Grandma. Caillou's mood changes when he discovers an old photo of a younger Grandpa and Grandma dancing. He gets more excited when he finds a first-prize ribbon they won at a dance contest. He wants to dance too! With Grandma as his partner, Caillou follows her lead and learns to dance in the living room. Soon Caillou is even inventing his own steps! The dance goes on and the park is long forgotten, even though the weather has changed and the sun is now shinning outside.