Thomas and the Great Discovery is a book.
Thomas was going to the wharf to deliver three flatbeds of logs, but fearing that he was going to be late, he uses an old track thinking that it was a shortcut. But instead, it was a track that lead to the lost town of Great Waterton! Sir Topham Hatt made plans to restore the town and put Thomas in charge. While Thomas is busy restoring Great Waterton, Sir Topham Hatt orders a new tank engine, named Stanley.
Thomas saw a freight car close to the entrance to Morgan's Mine but he puffs too fast and hits the truck causing it to fly into the mine. Thomas follows the truck but soon derails and trundels down the abandoned mine. Soon Stanley was wondering where Thomas was and so was the Fat Controller. He sent all the engines to look for Thomas. Stanley whistled at the entrance of Morgan's Mine and Thomas whistled back. Stanley enters the mine and soon pulls Thomas out.
A few days later Great Waterton was ready for the grand opening and Lady Hatt announces that Great Waterton was open again.
- Sir Topham Hatt
- Lady Hatt
- Sodor Brass Band
- Max or Monty (cameo)
- This book is based on the 2008 special The Great Discovery.