Caillou's All Alone is an episode in Season 1.
Caillou asks his mommy for some juice, but she says that she is too busy counting. Caillou decides that he can help her count and starts saying random numbers and causes a stack of paper to fall over. Caillou's Mommy is mad and asks him to go find somebody else to hang out with.
Next, Caillou finds his daddy who thinks he has just fixed the washing machine, but he hasn't; bubbles start abounding. Caillou's Daddy is mad and tells Caillou to go find Grandma. Caillou finds Grandma and he tells her about the washing machine.
Grandma politely tells him to leave because Rosie is taking a nap, but Rosie wakes up crying. Caillou finds Gilbert but he won't play with him either. He goes back to the kitchen, but his Mommy is still very busy. So, he plays in his room for a long time until his Mommy, Daddy, and Grandma come upstairs make sure he is okay. They ask Caillou what he is doing, and he replies, "Nothing, just playing." He seems quite happy.
- The crying sound effect used for Rosie is a stock sound effect normally used in other cartoons such as Arthur, which was also produced by Cinar, rather than her normal voice actress. This could indicate that this episode was first in production order and Rosie's actress was not cast yet. This sound was later used for a baby in Caillou Roars.