Thomas and Friends: The Secret Engine is a DVD special of TTTE.
Thomas and Henry are at the Steamworks due to Thomas needing to be repainted and Henry had an accident. The two are talking about Edward, who seemed to be very quiet recently. Victor thinks it's rude to talk about Edward behind his back and tells them to stop. They obey, but still wonder.
Meanwhile, Edward and BoCo are shunting Troublesome Trucks for Donald. When Donald comes, he thanks Edward and BoCo and rolls away. BoCo questions Edward's quietness. Edward just says he is tired. BoCo thinks Edward's hiding something, and Edward confesses he was. BoCo asks, but before the viewer can hear the secret, the screen cuts to another scene.
Percy is at a siding in Blue Mountain Quarry, Sir Handel sees Percy and goes to him. Percy explains he got in a big accident. Telling Sir Handel his coal bunker broke off. Before they can keep talking, Skarloey tells Sir Handel to get back to work, which he does. Percy just sits there.
Then, at Knapford Station, James, and Emily are arguing about who should be in the front of the goods train. Toby scolds the two and tells them to get to work. Then, Gordon zooms by, forgetting to stop at the station. Gordon seems to be unable to stop. He is launched right into a river, and the coaches as well.
James and Rosie take Rocky to Gordon, and the coaches are fished out. Gordon is very sick now, and James is covered in coal dust due to Emily stopping too quickly. Soon, all of the Steam Team, besides Edward, are in Tidmouth Sheds at night. A coal bunker-less Percy wonders where Edward is. Same with a damaged Henry, and purple Thomas due to a lack of blue paint. Toby decides to look, and exits Tidmouth Sheds.
Toby is looking on Edward's branchline. He runs into BoCo, who is also looking. The two split up. After a bit, they give up. Duck is told to look by Sir Topham Hatt the next day, and does. In some woods, Duck is searching, he hears the voice of Edward. Duck comes over, shocked to see a whole bridge. Edward explains that an old friend of his loved the bridge. Duck is confused. Edward just goes back to his branchline, awaiting his punishment. But, he doesn't get one.
Duck stays by the bridge, BoCo and Edward come over. BoCo wants to see what's over the bridge, and goes. Edward and Duck follow. The three all gasp at their sight. An old cabless engine. The engine is also shocked, due to him having met Edward and Duck before. Edward is surprised to see him, as he was his old friend he was referring to.