Isabel and her grandma are supposed to ride the Amtrak to Auntie Connie's house. However, something happens, and instead of getting on the shiny train, they find themselves on an old steam locomotive with other passengers who resemble the characters in the books Isabel has read. They travel a short distance before the train is robbed. That's when the adventure begins as Isabel and her grandma discover that the robbery is simply a cover for other types of illegal activities.