Caillou is very excited when his family decides to take a trip by train. After they have settled into their compartment, Daddy takes Caillou to explore the train. There is so much to see and do; Caillou visits the kitchen, the dining car and even the dome car! But when it's time to sleep, Caillou wonders where the bed are. Luckily, the train attendant holds the key to the mystery!