Thomas and the Great Discovery is a book based on the 2008 special The Great Discovery.
Thomas was going to the wharf to deliver three flatbeds of logs, but fearing that he was going to be late, he used 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 truck 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 trundles 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)
- There are a few differences between the film and the book:
- Thomas' race with James, Rolling River Bridge, Madge giving the news to the other engines and the accident with the trucks hitting the Water Works tower are omitted.
- Harvey lifted Thomas when he fell off the tracks, instead of Edward and Rocky.
- Thomas does not know about Stanley until his accident, unlike the special where he heard it from James by the Great Waterton Sheds.
- Thomas goes into Morgan's Mine right after Sir Topham Hatt tells him that Stanley will be in charge, as the tower accident was omitted.
- Thomas got stuck in the mine by coming off the rails, unlike the special where he was on a wooden raft floating down the underground tunnel.
- Stanley rescued Thomas inside the mine.