The Great Discovery is the 2008 special, and the second one to be released in the Thomas & Friends lineup of specials. It was released on DVD in the US on September 8th, 2008, while the DVD was released in the UK on October 6th.
It is almost Sodor Day, and everyone on the Island is preparing for the celebrations. Thomas and James are both racing to the Wharf, as whoever will make it to the Wharf first will be given a special job. When the two engines arrive at the Wharf, Thomas wins the race. The Thin Controller tells James that he will be working at the Wharf, while Thomas will work with Duncan to fetch lumber from the hills. Thomas is less than pleased, as he does not enjoy working with Duncan.
At the Transfer Yards, Duncan arrives with the trucks of lumber, when Thomas teases him for his small size. This makes Duncan cross, so he decides to play a trick on Thomas. He tells them that there is a shortcut that goes to the Wharf, and that he should take the line that leads to Rolling River Bridge if he wants to make his delivery quicker. Duncan shows Thomas the junction leading to the bridge, but is not aware that the bridge had been abandoned for a long time.
When Thomas arrives at Rolling River Bridge, he discovers that the bridge is very rusty and unstable. Just as he tries to cross the ravine, the bridge begins to collapse, so Thomas decides to take another track. As he heads down another disused line, he is amazed to find an old, abandoned town lying in the forest. Once when he leaves the town, he tells Madge about his discovery, and soon the news of the old town spreads across the Island.
Upon hearing about the discovery, the Fat Controller has Thomas take him to the old town. He tells Thomas that the town he has discovered is Great Waterton; long ago, the first steam engines on Sodor used to live in the town, and there was a waterworks in the town which provided the Island with fresh water, but people moved away, and the town was abandoned. He believes that restoring the town would be perfect for Sodor Day, and calls up Miss Jenny and the Pack for help. At the sheds, the Fat Controller announces that everyone will help with the reconstruction of the town, and that Thomas will be put in charge of overseeing the project. He says that in the meantime, a new engine will arrive and do Thomas' normal jobs.
At Brendam Docks, the engines gather round to see the new engine. A shiny, silver tank engine emerges from the warehouse, and the Fat Controller introduces the engines to Stanley, and all of the engines are amazed. Meanwhile, Thomas is helping with the rebuilding of the Great Waterton Sheds, where he will be staying during the town's restoration. Just then, James arrives, and tells Thomas all about Stanley and how everyone likes him. Thomas begins to feel jealous, especially when he sees Stanley pulling Annie and Clarabel and fraternizing with his friends. That night, when he returns to Tidmouth Sheds, Thomas is infuriated to find Stanley sleeping in his berth, and goes back to Great Waterton.
The next day, Thomas is determined to prove that he is better than Stanley. However, as he is pulling a train of heavy trucks, Thomas goes around a bend too fast and derails. As he was damaged in the accident, Thomas is taken to the Works by Edward, while Stanley does his work at Great Waterton. Upon returning after his repairs, Thomas is impressed by the sight of the station, but is upset to see Stanley. The Fat Controller tells Thomas that Stanley will continue to be in charge of the town's restoration, much to Thomas' dismay.
That afternoon, Stanley asks Thomas to shunt his train of stone for him until he returns to the yard. While he shunts the line of trucks, Thomas gets an idea, and decides to give Stanley an extra long train to prove to the other engines he is not as strong as he seems. When Stanley returns to the yard, he is surprised to find the heavy train, but hesitantly agrees to take it. As he heads up the steep hill outside the station, Stanley begins to struggle, and the coupling between him and the train breaks. The trucks roll down the hill and smash into the newly-built standpipe, which collapses to the ground. Depressed, Thomas leaves the station and finds an old track to be alone on, believing the other engines no longer want him. Stanley watches him from a nearby hill, and feels sorry for him.
At Great Waterton, the Fat Controller announces that, due to the destruction of the tower, work on Great Waterton will be delayed, and the town will not be opened in time for Sodor Day. The engines and the Fat Controller are cross with Thomas, and as they leave the station, none of them speak to him. Thomas feels terrible and knows he has let everyone, including himself, down.
That night, as the engines sleep at the sheds, Thomas decides to shunt the trucks of rubble away so that the other engines will like him again. As he shunts the trucks into their proper sidings in an old yard, Thomas notices a truck on a siding and decides to shunt it with the others, but he bumps the truck too hard and it rolls through an old mine tunnel. Thomas races through the mine and pursues the runaway truck, but does not notice a junction up ahead. The truck runs down the right track, but Thomas goes down the left one. Just then, Thomas notices that the line ahead is boarded-up and tries to stop, but he crashes through the boarded-up entrance and lands inside a flooded tunnel. As Thomas begins to drift down the tunnel, he notices that nobody will be able to find him.
The next morning, the engines gather at Great Waterton, but none of them know where Thomas is. The engines become concerned, and all across the Island, everyone begins searching for him, but no matter where they look, they cannot find him. Stanley goes onto a siding and believes that Thomas may have run away, and begins looking for him by himself, but finds no trace of him.
Meanwhile, down in the mine, Thomas is drifting down the mine faster than before, when all of a sudden, he charges through a wall of bushes, flies out of a waterfall and across a ravine, and begins rolling down a hill through bushes and trees. He comes to rest at the bottom of the hill beside a railway line, but is unable to get onto it. Suddenly, Thomas hears Stanley's whistle in the distance, and with the last of his steam, he whistles back. Stanley hears Thomas, and rushes over to him. Thomas tells Stanley all about his adventure in the mine and apologizes for his behavior, and Stanley forgives him. After the two engines are chained together, Stanley pulls Thomas back onto the rails, but his valve bursts, so Thomas shunts him back to Great Waterton, where the other engines are working. News of Thomas' return soon spreads, and all of the engines are happy that he has returned.
The next day, the tower has been rebuilt and is finished. The Fat Controller arrives at Great Waterton and announces that the town will be ready to open in time for Sodor Day. Thomas asks if Stanley can bring the Mayor of Sodor to the grand opening, and the Fat Controller agrees. When Sodor Day comes, Great Waterton is reopened. The celebration begins, and Thomas realizes just how important his friends are.
Does not speak
- Iron 'Arry
- Iron Bert
- Diesel 10
- Peter Sam
- Stephen Hatt
- Bridget Hatt
- Jem Cole
- The Refreshment Lady
- Cyril the Fogman
- Lord Callan