Luke is a young narrow-gauge engine.
Luke is a plucky-green Irish engine. He came to the Island of Sodor, which was a dream of his for a long time. He was lifted onto a large cargo ship, and was very excited. A Spanish speaking yellow engine who had ridden the boat all the way from Cuba was there when he came on. During the trip, a storm raged, breaking the chains holding the engine down to the boat. Luke was unaware of this development. After weeks or possibly even months, Luke and the yellow engine arrived at Sodor. The workmen were originally going to lift the yellow engine onto land as soon as they arrived, but Luke wanted to be the first off the boat. The workmen agreed, but when Luke was lifted up, he bumped into the yellow engine and he fell into the sea. Luke, ridden with guilt, thinking he had caused the engine to be scrapped, ran away and hid in the Blue Mountain Quarry.
A few years later, Paxton had an accident at the Blue Mountain Quarry, and Thomas was marshalled to do his work. Thomas saw Luke, and asked the other engines about him. They pretended to know nothing, but eventually revelaed that they were protecting him from being sent away from Sodor forever. He soon got close to him, and Luke told Thomas the story. Thomas did some investigating, and found out Victor was this engine.
Thomas told the engines that he found out that the yellow engine wasn't scrapped, but Luke and the other narrow gauge engines misinterpreted the situation, and thought Thomas had turned his back on them, and told Victor about Luke's secrets. Feeling betrayed, they all puffed away from Thomas. Determined, Thomas asked Rocky to lift him onto Owen and carry him up to the upper terrace. Thomas, being too big for narrow gauge rails, rolled out of control onto the edge of a cliff. Luke, realizing that he is the only engine that could rescue Thomas, pulled him to safety. The truth was soon revealed, and Luke and Victor are now on good terms! Now, Luke enjoys his new life on the Island of Sodor, and is thankful he no longer has to hide away in the Blue Mountain Quarry.