The Steam Team notice that Thomas and Emily have been spending every night in Knapford Sheds, until they realize that a very special milestone is approaching. This year marks Thomas and Emily's ten year anniversary of being a couple, and to celebrate this glorious achievement, Thomas and Emily have been making plans to ensure that this will be their most magical day of all.
The "World of Tomorrow" Technology Fair is underway, while Thomas was initially the engine to be worried about new inventions taking over the railway, he soon learns that they have nothing to fear. However, now the all the other members of the Steam Team are worried instead, especially Emily. Among all of the festivities, two crooks are plotting a plan to make themselves rich.
With the arrival of Sir Robert's old friend, Ruth, there's to be a special Technology Fair at Ulfstead Castle, where inventors from all over the world will gather together in order demonstrate their inventions. While the preparations are underway, Luke and Millie won't have any time to see each other during the Fair, so they meet up on the night before the preparations begin.
Bill and Ben have been held up in their shed for weeks after their carelessness endangered Thomas and Emily at the Clay Pits, and by now they wish they could prove that they are sorry. Emily, however, is still very skeptical about the twins having learned their lesson, but with Summer proving to be as busy as ever, Bill and Ben will have to be let out of the shed sooner or later.
November has come, and Gordon and Rebecca still ponder over their love. With Christmas coming soon, they start to feel more romantic sensation for each other. Bonding together even more, the two express engines decide that it's time for their friends to learn about their relationship, but Gordon fears how his brother will react. Originally one long chapter, now split in three.
George the Steamroller is tasked with helping with the new road development close to the railway, however his infamous anti-rail behaviour is worse than ever before as he causes a great deal of stress and trouble for Emily and Gina, until George finally goes too far, forcing the Sodor Island Council to take action. Originally one long chapter, now split in three.
A safety inspector comes to the island to perform an emergency drill to test how well the engines respond in an emergency. However, when the pretend emergency turns into a real emergency, Emily's quick and sensible thinking saves the day, earning her the title of official safety engine and finally becoming the NWR's Number 12. Originally one long chapter, now split in two.
When Rebecca tells James he could be a comic-book super-engine, he takes her seriously, and Rail Rocket is born. James tries using his new superhero identity to help others in need, but doesn't have as great a success as he hoped for, until he saves Rebecca. When Molly learns of this, a night of superhero friskiness ensues. Originally one long chapter, now split in two.
It's nearly Christmas once again, and Molly is full of festive spirit as she's tasked with helping to set up the Tidmouth Christmas Market. But James isn't as cheerful because he's been tasked with pulling the Flying Kipper once again. Unfortunately, James once again suffers from a mishap involving the train, and Molly is determined to help her Radiant Ruby get over it.
Thomas returned from his trip to Australia in time for Christmas, to make sure he and Emily share it together after they were separated the last time Thomas was in Australia during winter. But when Thomas is tasked with going to the Mainland on Christmas Eve, a blizzard makes it so that he might not get back to Sodor in time. Will the stars be able to guide Thomas home?
After the recent summer gales that caused a lot of trouble for the engines, Thomas, James and Emily decide to make up a story about how they are given a chance to have their very own sheds built and they each choose different ways to make them. But then a Big Bad Storm arrives and tries to huff and puff and blow their sheds down.
It's Valentines Day and love is in the air as Thomas and Emily celebrate their first Valentines Day together.
Emily is upset that she has never had a really exciting delivery but Thomas is there to reassure her that her chance will soon come to her eventually.
Thomas and Emily have secretly loved each other for many years, but when Duck stays in Tidmouth Sheds one night and leaves Emily to sleep alone, will this hinder Thomas and Emily's relationship or will it allow them to reveal their deepest feelings to each other?