How the Diesel Stole Christmas is the 3-part 2013 Christmas Special. The three parts were uploaded on December 7, December 16, and December 24, 2013.
The special starts with Thomas delivering a Christmas Tree to Ffarquhar station, much to the excitement of Percy, Toby and Daisy. The other engines on the Island of Sodor are excited for Christmas, except for Diesel, who hates Christmas a lot.
Diesel's grumbling angers the other engines and scares the Fat Controller's grandchildren, much to his dismay. Later on, the Fat Controller scolds Diesel for scaring his grandchildren and ruining a holiday for the engines. Diesel apologizes and leaves. While sitting in the shed, Diesel tells Diesel 10 (in Diesel's figure mind) about how miserable his life has been, Diesel 10 reminds him that the engines don't like him now and that's all because of Christmas. Later the Fat Controller tells Diesel that he will deliver the food for the Christmas Feast.
Diesel picks up the food from Crovan's Gate as he is told, but hates the smell and doesn't listen to Skarloey and Ivo Hugh's warning about transporting food. Later on, when he reaches Wellsworth, Diesel can't stand the smell any longer. He rolls onto the siding to rest, but leaves the trucks of food in the middle of the line, ignoring Edward's warning.
15 minutes later, Diesel's driver tells him that his break is over and has to clear the line to allow Gordon to pass with the Express. However, Diesel refuses to move, still not recovered from the smell. His Driver tries to order Diesel to move, but to no avail. Gordon rolls into the station but cannot stop in time, crashes into the vans of food, derailing him and Edward and leaving them all covered in squashed food, much to their anger. Gordon angrily asks who left those vans in his way. Edward tells him that Diesel did it, which Gordon seethes with growler. They know that some passengers have been injured and Stanley appreciates having food in his boiler.
Later that evening at the Diesel Works Shed, the Fat Controller reprimandes Diesel for his actions and tells him that 31 people were injured (some seriously), and it was miracle that no one died in the accident, but now they will have to spend Christmas in hospital. He also tells Diesel that more food will have to be quickly prepared for the feast. Diesel promises to be more careful tomorrow, but the Fat Controller tells him he can't leave the yard for two months. Diesel tries to explain but it is no use, the Fat Controller then tells Diesel off and calls him a "god damn fool" and storms off. Henry, who has overheard all this, calls Diesel an "ugly fat Grinch face" (after Diesel asks what was he staring at) and huffs off to Tidmouth Sheds and calls him a "Son of a Scrooge".
When Henry gets to Tidmouth Sheds, he tells the other engines about the Fat Controller punishing Diesel.
On Christmas Eve, Bertram wakes up the other Skarloey Railway engines while the other engines gossip about Diesel's incident and stupidity.
The news of Diesel's incident so spreads across the Island of Sodor.
Back at the Diesel Works Sheds, Diesel is still in a bad mood. He wants to find a way to stop Christmas from coming. He states for 56 years he's put up with it now. He eventually gets a wonderful awful idea, and tells Arry, Bert, Paxton and Sidney that they are going to steal Christmas.
Meanwhile, the engines are trying to finish up their jobs so they can get home in time for Christmas. Later that night, the engines are too excited to sleep and wish each other a Merry Christmas and a Happy New Year.
Later, the five diesels prepare to steal Christmas. Diesel is disguised as Toby, Arry and Bert are disguised as BoCo, while Sidney and Paxton remain undisguised. Once they are ready, they set off. Diesel, Paxton and Sidney take down the decorations and Christmas Trees along the Main Line, while Arry and Bert derail and wreck things along the branch lines. Some time later, the five diesels are at the Docks when Harold the helicopter, who is on his midnight lookabout, approaches them. Diesel sees Harold coming and tells the other diesels to stay calm. Harold asks them why they are out this late on this time of Christmas Eve. Diesel (who Harold mistook for Toby) lies that they are delivering the last goods and are moving the Christmas Tree at the Fat Controller's request. Harold then buzzes away, much to Diesel's relief.
The diesel's last stop is Tidmouth Sheds. But unknown to them, hiding behind the sheds, a hallucination of Lady is spying on them, knowing what they are up to. Right now, Diesel begins to feel that what he's doing isn't right, but he forced to go on. Once the last decorations are down, Diesel tells the other four diesels to dispose the decorations and tress at the smelters and ditch the costumes before they get there.
At the smelters yard, the diesels are about to burn the decorations when Lady pops out of the molten metal and tells Diesel the he has corrupted himself and his friends and that they must snap out of ruining the holiday. She also tells the engines that Diesel only hates Christmas because he never celebrated it on his old railway before coming to Sodor. She also tells him that she cannot decide whatever to save the decorations or not. And with that, she disappears into the molten metal.
Diesel decides not to listen to the magical engine and decides to destroy the decorations before Paxton tells him that it's already dawn. Diesel tells the other four diesels he can't wait to see the other engines to cry "boo hoo hoo" after the find out all their decorations have been stolen.
At Tidmouth Sheds, the engines wake up to find that the decorations have disappeared, thinking Christmas must've gone. They are all sad, but Gordon says that Christmas isn't gone and it is still here, much to the confusion of Henry, who asks how that can be since all the decorations are gone. Gordon explains Christmas can never be taken away from them and that it is not about decorations, parties, or presents, it's about being together and happiness. He states even if he was in a scrapyard about to be melted down, he would still have a merry Christmas. Gordon then screams: "In the name of Awdry and Allcroft, MERRY CHRISTMAS!!!! The other engines all agree despite what has happened, they will still have a merry Christmas.
Meanwhile, Diesel is excited and waiting to hear everyone cry, but is surprised to hear everyone singing and happy and that he and his friends didn't stop Christmas from coming, it came! Diesel is surprised that Christmas had still came, despite not coming with ribbons, tags, boxes or bags. His 2006 model suddenly transforms into his 2012 model, much to his surprise and pain of the other diesels watching. After being reformed, Diesel has discovered the true meaning of Christmas and decides to set things right.
At Knapford Station, Thomas wishes Donald and Douglas a Merry Christmas while Donald wishes Thomas the same thing. Douglas notices Diesel returning with the decorations, the other engines are surprised and angry, thinking he stealing the decorations. Diesel explains himself to the engines and apologizes for his actions. This causes the hallucination of Diesel 10 (who has been following Diesel and telling him negative this all throughout the special) to cry out in agony and disappear.
The Fat Controller comes by, hearing Diesel's speech, tells him that he forgives him for stealing Christmas and forgives him for causing the accident two days earlier. Edward tells everyone they should get the decorations quickly put back up.
Later that evening at Tidmouth Christmas Party, Henry tells Gordon and James a dirty joke, much to their disgust. Thomas arrives and surprises Toby and Percy with his new 2012 model. Annie and Clarable have also gotten new models. Arry tries to hit on Mavis, but she tells him to get a life. The Fat Controllers wishes the viewers a Merry Christmas and tells them to look forward to a good 2014. He also thanks the viewers and subscribes. Watching from a distance, the hallucination of Lady agrees that Diesel's Christmas is very merry.
- Donald and Douglas
- Bill and Ben
- Arry and Bert
- Sir Handel
- Ivo Hugh
- Sir Topham Hatt
- Stephen Hatt
- Bridget Hatt
- Diesel 10 (appears as figure in Diesel's mind)
- Wretch (appears in flashback, does not speak, not named)
- Hiro (cameo)
- Stafford (cameo)
- Rheneas (cameo)
- Peter Sam (cameo)
- Rusty (cameo)
- S.C.Ruffey (singing only)
- Splatter and Dodge (original script only)
- Annie and Clarabel
- The Grinch (appears in pictures, does not speak)
- Scrap Engines (does not speak, appears in flashback)
- Bertie (appears in picture, cameo)
- Henrietta (appears in picture, cameo)
- Stephen (cameo)
- Salty (cameo)
- Toad (cameo)
- Horrid Lorry (cameo)
- Spencer (deleted scene cameo)
- DarthWill3: Diesel
- Trevor O'Neal: Lady and Paxton
- EnterprisingEngine93: Bertram and Edward
- RightonTracks10: Thomas
- James Riddle: Toby
- Andrew Homer: James
- Connor O'Connell: Sidney
- MallardFan62: Duck (archive audio in first part)
- Knapford Productions: BoCo and Oliver
- CurtyLara2 (SamTheTrainFan): Bill and Ben (archive audio)
- Thurl Ravenscroft: S.C. Ruffey and Trucks Singing
- Thomas1Edward2Henry3: Everyone Else
- This special is obviously based on the book How the Grinch Stole Christmas by Dr. Seuss.
- This marks the first appearances of DarthWill3, Trevor O'Neal, RightonTracks10 ., Connor O'Connell, and KnapfordProductions as voice actors.
- This is the only time BoCo is voiced by KnapfordProductions, as he was just a temporary actor until a replacement for Tommy Davias was found, which turned out to be Andrew Homer.
- Bill and Ben's lines were recycled from Bill and Ben the Brave Brothers of Brendam because CurtyLara2 never responded to messages. The same thing applied with MallardFan62, but only in the first part. His lines were recycled from A Wretched Day for Henry and James and Gordon Goes Swimming. MallardFan62 was just having computer problems and the first part had already been uploaded by the time he had given the lines. To add to that, Rusty and Peter Sam were to have speaking roles but had to be made silent for the same reason.
- This marks the first appearance of SI3D's 2012 Thomas, Diesel, Annie, and Clarabel models, but only near the end.
- This special features music from Thomas and the Magic Railroad, Star Wars Episode II: Attack of the Clones, Doctor Who, and Inception as well as the famous song "Your a Mean One Mr. Grinch", written by Albert Hague and preformed by Thurl Ravenscroft.
- The regeneration of Diesel is obviously based on the regeneration idea from Doctor Who. In fact, the scene features a low pitch version of Vale Decem, which is heard during the 10th Doctors regeneration into the 11th.
- Gordon was originally going to have the role of Cindy-Lou Who, but the idea was dropped because of length issues.
- In the original script, Diesel 10 wasn't a figure in Diesel's mind. Diesel and his minions met him at Barrow-in-Furness as well as Splatter and Dodge to get equipment for their burglary. It was dropped because it didn't seem right to have these characters in real form, as they were only meant to be in Thomas and the Magic Railroad.
- In the original script, Diesel dressed up as Bert the Brickworks Engine from WildnorWester3D instead of Toby. This was changed for several reasons: No one would know who Bert is if they saw him (like Harold), Toby would be a more suitable disguise because of his boxy shape, and there was uncertainty that using an Asperger Syndrome Awareness character could promote controversy.
- Stafford and Stephen were supposed to have speaking roles, but Thomas1Edward2Henry3 forgot to film them.
- Stock footage from A Wretched Day for Henry and James is used as well as real pictures from Thomas and Percy's Christmas Adventure, Trouble in the Shed, Thomas' Christmas Party, It's Only Snow, Edward, Gordon, and Henry, Thomas and the Missing Christmas Tree, Escape, Not So Hasty Puddings, and the Railway Series book, Stepney the Bluebell Engine.
- The drawings during the title sequence were drawn in Microsoft Paint.