Caillou is ready for the curcus but he can't go; what will he and his dad do for fun instead?

Caillou is playing dinosaur hunter with Gilbert the cat. Caillou goes for a snack, and when he comes back there's no sign of Gilbert. He's disappeared! Mom says Caillou will have to be a detective, so together they search the house for clues. Eventually they find Gilbert curled up fast asleep in Caillou's bed.