Caillou is building a beautiful castle that his sister Rosie accidently destroys. Upset and angry, Caillou vents his frustration. Mommy listens to him, consoles him, and explains that Rosie did not do it on purpose.

With Mommy's help, Caillou takes his first steps toward tolerance and learning to compromise.

Grandma and Grandpa have invited Caillou to spend the day at their house! They play cards, paint a chair, and even have pancakes for lunch. Later, Caillou helps Grandma plant flowers. He has so much fun that he doesn't want to go home. Caillou loves visiting his grandparents! This book relates the wonderful relationship between a child and his grandparents. Whereas parents are often preoccupied with the obligations of the everyday life, which is often stressful; grandparents have more availability. Parents are concerned by their child's education; grandparents have only their affection to give to their grandchildren - all their affection. This book speaks of love. The love grandparents have for their grandson and the love a child has for his grandparents.