The Runaway Caboose

S2 E16: Mary, Laura, and Mr. Edwards' adopted son Carl long to get a first-hand look at the kinds of trains they learn about in school. The kids eventually con their parents into letting them go on a business trip with them. While messing around on a caboose at the train station, the children are in for the ride of their lives when it detaches from the rest of the train and runs loose.