Caillou and Sarah are playing together when Caillou notices his friend wiggling her loose tooth back and forth. He asks her about it and she crouches down to show him. She uses her tongue to wiggle it back and forth, explaining that soon it will fall out. At first Caillou is horrified. Sarah laughs and tells him baby teeth are supposed to fall out. It makes room for the grown-up teeth. And besides, when you start losing teeth, the tooth fairy brings you presents. That gets Caillou's attention.