Thomas sees a glorious rainbow in the Sodor sky, upon the ending of a great storm. After confiding with Edward, who says that rainbows hold something magical at the end, Thomas sets out to find just what that something could be, but neglects the fact he has work to do.

Milk is used to make ice-cream and butter is used to make cakes. Thomas must collect both of these ingredients so as those two very things can be made for the summer party. However, it would seem all is lost when Thomas travels much too fast with the milk, which shakes it around so much that it turns to half-way butter…

Everything is happening on the Narrow Gauge Railway. There is the new Controller, Mr. Percival, and there is the new locomotive, Mighty Mac. But this is no ordinary locomotive; in fact it has not one smokebox but two! At one end there is Mighty and at the other, Mac. On their first job they already start fighting, and in this case, over which way they should go to reach the proposed destination. Will they be able to reach a resolution, to work as one?

Molly, a lovely new engine with striking yellow paintwork and four, large drive wheels, but Molly doesn’t think pulling empty trucks is lovely. She wants to pull a nice, fully loaded goods train. Thomas makes a suggestion to her, but is it a wise suggestion? Molly, nonetheless, takes heed.

Pompous as ever Gordon creates a complete set of rules for the engines to strictly adhere to, upon their teasing about the loud rattling that has started to makes itself heard from him.

It is Sir Topham Hatt's mother’s birthday, and he wants to make it as special a day for her as possible, by taking her on a birthday picnic. But of course, for such a special occasion, an equally special location there should be to compliment – but just where?

A brass concert is being held, which Rusty the Diesel will be playing in, utilizing his rather musical two-toned diesel horn. But on his way to the venue, overexcited Rusty finds himself clean out of oil. Without him, the concert will surely have to be canceled.

Toys, toys, toys. All children love toys. In fact, a new Toy Shop is opening at Knapford, which will certainly make the local Sodor children very happy indeed. And Thomas is to be taking some lucky children to the big, grand opening. But will they miss the whole event upon Thomas being Thomas?

The dinosaurs may be gone, but they still live on in the findings of their remaining bones, and it is such a find that has been made on Sodor. Rheneas & Skarloey both want to collect the bones, which need to be taken to the all new Transfer Yards area that has been constructed. But because of Skarloey’s clumsiness, Rheneas decides he will do the important work on his own, leaving poor Skarloey in the cold. What he fails to realize is dinosaur bones can be more heavy than one may think…

Thomas sees a new engine, who seems to be getting along very well with diesels, Iron ‘Arry & Bert, so well in fact that they’re laughing and everything. But the engine is steam powered. A steamie who’s friends with diesels? Certainly this cannot be? But does Thomas have his facts straight? Surely he couldn’t be mistaken?

Toby finds out that The Steam Team are receiving brand new coats of paint – except for him. The Sodor Museum is soon to open, and Toby fears that he is not being repainted because the Fat Controller is going to give him to the Museum! Is Toby the Tram Engine destined to become a museum-piece?

Thomas has to deliver chickens to Brendam Docks. But Thomas wants so much to go to the carnival that has arrived, that he tries to rush his job through to make it there sooner, which proves not to be the wisest of choices.

Peter Sam wouldn’t even think of believing in Skarloey’s story about the magic lamp belonging to the legendary engine, Proteus. But before long, Peter Sam starts thinking otherwise about the lamp, so much so that he loses his way on a night shift…

Thomas is to haul a special statue from Brendam Docks, which is in celebration of the railway’s many, fine years of service. When Thomas observes the shape of the soon to be monument beneath the tarpaulin, he is sure that it is of himself. How right or wrong could Thomas be?

Henry fears the Fat Controller will use his favourite tree for a new flagpole, due him accidentally causing the one which was going to be used to be destroyed. Henry can’t bare the thought of losing something so precious to him, so sets out to find an alternative replacement.

Percy and Toby do not approve of Emily’s desire to be Miss. Know-It-All. Emily goes so far in fact that her antics lead to terrible confusion (and delay). Will Emily see any sense?

It's Thomas's day off, and new diesel engine, Dennis, is to deliver to the school some new roof tiles for him. But Dennis is as lazy as can be, and tries to trick Thomas into still doing the work by pretending he has broken down. But such a lie comes back to haunt Dennis.

Thomas and James have both been given splendid new trucks to pull, from the Fat Controller. The two engines decide they will have a little competition between themselves to see who can keep their train of trucks looking spic 'n' span, with quite some results…

On one day in particular, problem-engine Duncan is feeling rather adventurous. He is supposed to be taking trucks loaded with coal, but decides to head down an old line instead for a bit of fun. But perhaps Duncan should have stuck to what he was supposed to be doing, as he soon finds in one of the worst possible ways.

Is there really such thing as a curse? After Diesel tells of the sea cliffs being cursed, Thomas thinks so, and he has to travel along them on this day! It’s his route to take on an important job assigned, but will Thomas dare take it?

Skarloey sets out to try and prove himself to the others by being the bravest locomotive ever – by attaching himself to the Incline winch. Not smart…

Poor Edward isn’t in the best of condition, and fears the Fat Controller will send him to the scrap heap. As a gesture of kindness, Thomas says he will do Edward’s work for him. Later though, both engines find out that Edward’s situation isn’t as dark as it would seem…

Best friends, Thomas and Percy, greatly want to see for themselves a golden eagle which has said to have been recently flying in Sodor’s skies. The engines decide to halve one another’s work, so as they have more free time to spare that day to try and spot the wondrous bird, but will their little plan work like the charm they hope?

James and Edward both want to pull the presents train for Christmas. The Fat Controller declares that whoever finishes their day’s work first shall be able to take it. And so the race for the presents train begins…

Thomas and Diesel have to collect flour, needed ready for the following day, from the Flour Mill. But tonight is Halloween, so Diesel decides to take advantage of this by trying to frighten little Thomas on their way to the Mill. Thomas, though, comes up with some surprises of his own…