"Dear Christopher, here is your friend Thomas the Tank Engine. He wanted to come out of his station yard and see the world. These stories tell you how he did it. I hope you will like them because you helped me to make them! Your loving daddy..."
Once upon a time on the Island of Sodor in the 1920s... many of the big tender engines are teasing Edward that he will not be allowed out because he is too weak, but when the driver sees him upset he offers to take him out. From there a series of grand adventures begins as our guide is Lady the Golden Engine - our singer and storyteller - as a bullysome quintet of big tender engines tries to take some of them under their wing like Gordon and Henry only to fail. Soon, a small engine named Thomas comes to straighten out Vicarstown Yards but will long to see the world outside the yard. After helping rescue a new engine named James who is also eager to prove himself, Thomas gets to run the restored branch line from Tidmouth to Ffarquhar on the western side of Sodor. Soon, labor difficulties and the pace of modernization begins to cause problems for the big engines that only an engine called Percy can help sort out and Thomas gets a new recruit for his branch line in Toby to help out with stone deliveries along the Quarry Tramroad. Henry soon gets a long-overdue rebuilt from a male LNER hybrid engine into a female LMS engine as a new lease on life.