Caillou has important stuff to tell Mommy. Rosie tore up a book and he drew her a picture and wants to show it to her. Every time he tries to speak to her though, he's interrupted by the ringing of the telephone and Mom's forced to ignore him. Then a call comes in and Mom hands the phone over to Caillou. It's Grandma. She comes over with a dog she regularly dogsits, Rover. When the phone rings, Rover goes nuts and Caillou discovers that he and Rover have something in common.