The DC Super Engines is a very special episode.
When Harriet Turtle loses her toy cat Lilly Kitty, Super Tank and the DC Super Engines must help her find her while looking for a mega mystery to solve.
As the Episode Begins, Thomas, Diesel, Spencer and Percy are investigating a weird sound. Thomas heard a cry for help. So, Spencer sounded his whistle and the DC Super Engines were formed. Super Tank, Bat Diesel, Wonder Engine, Spencerborg, Robin, Cat Engine, Super Girl Tank, Raven and the Flash see Harriet Turtle running towards them. Thomas and the others rushed to see why Harriet was in such a panic. They hurry into Tidmouth Sheds. Thomas, who's superhero persona is Super Tank, asks Harriet why she is in such a panic. She tells Super Tank that she's lost her toy cat Lilly Kitty and can't find her anywhere. Suddenly, Raven, who is the superhero persona of Belle, uses her mind reading powers to tell what Harriet wants the DC Super Engines to do. Then the mystery begins. Super Tank tells the DC Super Engines that best way to solve the mystery is to retrace Harriet's steps. And that's when Super Girl Tank, the Superhero persona of Rosie, asks Harriet where she was right before she found them. Harriet explains that she was at a tea party. Super Tank leads the DC Super Engines to Harriet's tea party. Super Tank finds out that Lilly Kitty is normally always lost right where Harriet left her. Then, the Flash, the superhero persona of James, finds a set of muddy footprints made by Harriet. And finds a clue, a whole line of Harriet's footprints. And continue discovering. And soon, the DC Super Engines find out that Harriet drew a picture of the Clay Pits. Then, Raven works out a tiny steam shovel in the corner, thinking it could be Marion. And Super Tank leads them to the Clay Pits. And soon discovers that Marion was in the picture that Harriet drew. Then, Marion spots the DC Super Engines. Super Tank found out that Harriet drew a picture of Marion. Super Tank was Surprised to see this. Then, Marion leads the DC Super Engines to the place where Harriet drew her picture. They follow her to a cliff. And soon, they find Lilly Kitty in a small hole. They use a shrink ray to get her out. and goes in. After getting Lilly Kitty out, they return her to Harriet. Thomas is pulling into Knapford the next day. When he was struggling, Thomas saw Harriet with Lilly Kitty. Thomas was happy, Harriet gave him a kiss. Everyone is pleased. Spencer claims to be seeing an invisible villain. It was Clone Thomas the Tank Engine. Then the DC Super Engines battle The Clone. and then Super Tank uses his eye lasers to burn it to ashes. And saved the day. Everyone thanked the DC Super Engines. For helping them. And Everyone else gives them a smile. Everyone celebrates as the episode ends. In a post credits scene, the real DC Super Engines try to find their dopplegangers. That makes things funny. The real Super Tank thinks that their dopplegangers are villains in disguise. That's very good. The screen then fades to black.
- This episode is a mixture of DC Super Friends and Thomas & Friends.