Winnie the Pooh and his friends (along with the Powerpuff Girls) journey back to the Island of Sodor to meet up with Thomas the Tank Engine once again and prove to Spencer and the Rowdyruff Boys (whom are friends of Spenser) how strong and fast Thomas can really be. During the race, Thomas' brakes got broken and he and our heroes race very fast to an old track where they met an abandoned and old Japanese Engine called Hiro who was forgotten for so many years. Now with new friends of Winnie the Pooh: Victor (who was in charge of the Sodor Steamworks) and Kevin (a little crane who works with Victor in the Steamworks), it's up to Thomas, Pooh and their friends to help restore Hiro and keep it a secret from Spencer and The Rowdyruff Boys.
- The Powerpuff Girls and the Rowdyruff Boys guest star in this film.
- The Rowdyruff Boys will be working with Spencer.
- This film takes place after Pooh's Adventures of the Powerpuff Girls Movie and Pooh's Adventures of the Powerpuff Girls: The Boys are Back in Town.