Thomas the Tank Engine works at the Big Station, fetching coaches for the bigger engines. He keeps teasing Gordon the Big Engine, making him very cross. When the Shunter later accidentally forgets to uncouple Thomas from Gordon's coaches, Gordon decides to be really fast to tire Thomas out.

Edward is feeling sad, as all the other engines are bigger and younger than him. But when Gordon gets stuck whilst pulling trucks up a hill, it's Edward to the rescue.

Henry the Green Engine doesn't like getting his paint wet - so refuses to come out of the tunnel. The Fat Controller tries everything, including getting Thomas to push Henry out but the big green engine still does not move. In the end, the Fat Controller orders a brick wall be built to block the tunnel entrance, meaning Henry stays in the tunnel forever...

Henry is sad that he is stuck in the tunnel, and Gordon is having fun teasing him whenever he passes. One day Gordon's safety valve bursts just outside the tunnel. Edward is the only other engine available, but the train is too heavy for him. How could the situation possibly be resolved?

Thomas wants to pull a train instead of just shunting coaches for the big engines, who laugh and say he wouldn't be able to do it. One night Henry is ill, and next morning he still isn't better. He is due to pull the morning train, and when no other engine is available, Thomas has to pull the train. He is so excited, he doesn't notice until too late that he has started before being coupled to the train, leaving his coaches and passengers left stranded at the platform!

Thomas is bored, and when one night Edward offers to swap duties with him for the next day, Thomas takes up the offer. This involves taking Edward's trucks. However Thomas is not used to trucks...

Thomas is in the yard shunting when new engine James rushes past with a goods train yelling for help. James has wooden brakes and the trucks are pushing him down the line. The alarm goes - James has crashed into a field of cows. Thomas has to get the Breakdown Train and help James. Afterwards, the Fat Controller gives Thomas a very special reward.

James the new engine has to pull some coaches with the help of Edward. They do very well but James is so excited that he accidentally showers water all over the Fat Controller's new top hat! Later on he is pulling more coaches and bumps them so hard that a brake pipe is damaged. Newspaper and a leather bootlace could temporarily mend the problem, but only a passenger willing enough to hand over their laces will the train be able to continue...

James is feeling sad as he is still staying in his shed for being naughty. Eventually the Fat Controller lets him out to pull a goods train, but the trucks don't want to be pulled by James and misbehave. Whilst pulling them up Gordon's Hill, a coupling breaks and the last few trucks roll back down the hill. James goes to get them (they were stopped by the Guard) and starts on up the hill once more...

Gordon boasts to James that he is the only engine who can pull the Express. One day he sets off with it, but due to points problems he comes back to the station feeling very sheepish. Another engine will now have to take over the job of pulling the Express for the day, but who will it be?

One day Thomas is late with his train due to Henry being late at the Junction, and when the Guard blows his whistle Thomas zooms off - without giving the Guard enough time to get on the train! Annie & Clarabel try to stop him, but Thomas continues to steam on!

Thomas has a desire to fish, and the others tell him "Engines don't fish!" When the water tower is out of order, Thomas has to take water from the river via a bucket. When suddenly he feels like he's going to burst, the Driver and Fireman look inside his tank and discover something rather unusual...

In Autumn, Thomas stops by a signal. There he meets Terence the Tractor, and teases him about his caterpillar tracks. When winter comes, so does the snow. Thomas refuses to wear his snowplough, and when he does he breaks it. Due to this he ends up getting stuck in the snow...

Bertie the Bus challenges Thomas to a race, to see who can get to the end of the line first. Thomas faces obstacles such as stations, signals and a slow start, Bertie has bus stops and traffic lights - who will win?

Gordon has to pull his train backwards due not trying hard enough to move into the correct position on the turntable, so as to be turned around. And when James gets on the turntable, the strong sea winds spin it round much too fast. The two, plus Henry, are very cross about the the unfortunate events that happened to them and so all formulate on a plan...

Henry, Gordon and James decide to go on strike, declaring that "Tender Engines don't shunt!" The Fat Controller sends Edward to do the work; but when poor Edward is being teased, the Fat Controller then decides to buy a new tank engine called Percy.

After being shut up for days in the shed, Henry, Gordon and James have been let out to work again. So the Fat Controller sends Thomas, Edward and Percy to play on the Branch Line. But Percy, however, becomes a little too cocky for his own good and suddenly finds himself on the Main Line - and on a collision course with Gordon...

Henry keeps feeling ill, unlike the other engines. It turns out that Henry's firebox is much smaller than the other engines', so the Fat Controller orders special Welsh coal that will allow Henry to work better. The Green Engine is thrilled with the results.

One winter's evening, Henry is excited to be given the chance to pull the fish train that the men call, "The Flying Kipper". Unfortunately, snow and ice result in an accident. The Fat Controller decides to send Henry off to the Works at Crewe, where Henry will unknowingly be given more than just a repair job...

Gordon becomes a little too above himself but learns a lesson when his whistle valve comes out of place causing quite a noise!

Meanwhile, some boys also soon learn a lesson after throwing stones at Henry and his coaches from an overhead bridge.

We meet Toby the Tram Engine and his coach Henrietta, who both work hard on their little line. One day, a stout gentleman (the Fat Controller), his wife and grandchildren, Stephen and Bridget, come to visit and become very fond of Toby. Some months later, the line is sadly closed, but little does Toby know he has been saved by a letter from a certain personage...

There is a Quarry at the end of Thomas's Branch Line, and he has to take the trucks to and from it. One day a new Policeman starts work and tells Thomas off because he has no cowcatchers and sideplates. It turns out this is the Law, so the Fat Controller will have to build them for Thomas. Thomas says he will look like a tram. But rather than give Thomas a tram overhaul, a much better idea has come into the Fat Controller's mind...

Toby and Henrietta are old and shabby looking. James remarks about how dirty they are, and says how he'd never be seen looking like that. James then has to pull a goods train along Gordon's Hill, but the trucks push him down and up ahead, a train of Tar Wagons lies...

Gordon is in disgrace after falling in the ditch. Thomas teases him about it, saying he has, "A funny, musty, sort of smell!"Later, Thomas has to deliver trucks to an old Lead Mine. The ground beneath the rails running overhead is weak and whilst it can support the weight of trucks, it can't support the weight of an engine. But Thomas ingnores the "Danger" signs.

It's Christmas on the Island of Sodor, and after Edward reminds the engines of last Christmas when an ill Mrs Kyndley waved her dressing gown out of her window to save Thomas from a landslide, Thomas decides to thank Mrs Kyndley properly by having a Christmas party for her. The Fat Controller agrees. However, on the day of the party, Mrs Kyndley is trapped in her house by snowdrifts, so Thomas, Toby and Terence go to her rescue.