A new Search and Rescue Centre is being built on the Island of Sodor. Special deep red 'Jobi Logs', found far away on Hiro's Island, are being used to make the centre. All the engines are very excited and all want to help deliver the Jobi logs to the Rescue Centre. Diesel, convinced that he is better than the 'steamies', decides to take the Jobi logs to the rescue centre himself and races down the tracks with the Jobi logs. Thomas sees that Diesel is going too fast and chases after him. The chase results in an exciting rescue as Thomas saves Diesel from falling over a cliff edge but the Jobi logs crash into the sea below - now there is no wood to build the Rescue Centre. As a reward for his daring rescue Thomas gets to visit the mainland. Thomas waves goodbye to his friends at Brendham Docks and heads across the sea to the mainland. That night Thomas becomes separated from the ship and ends up alone and stranded on the mysterious Misty Island - a wild and wonderful island with a multitude of secret hide outs, rickety tracks and bridges. Thomas soon meets the islands' inhabitants -- three funny logging locos called Bash, Dash and Ferdinand.