Salty, an old diesel, arrives on Sodor. He loves working by the sea but is most disappointed to find that the Fat Controller has sent for him to help out with the work at Centre Island Quarry, resulting in him of course not being able to work by the sea as he had hoped for. However, Salty is soon given a pleasant surprise...

Harvey the Crane Engine arrives in Sodor on trial. Some of the engines tease him for his strange looks but when Percy has an accident with some trucks, they soon change their minds...

Percy likes taking the Post Train but when he is held up at a broken signal one day, Harold decides to deliver the loads instead, but all at once, which turns out to be a very big mistake!

Thomas, by accident, discovers an old sentinel lorry named Elizabeth who has been left in a shed for years.

Cyril is a fogman and the engines like him a lot. He puts out detonators to warn them when there is fog ahead. However the Fat Controller decides to replace him with a very loud fog horn. The foghorn however causes a rockslide which crushes the foghorn, and Thomas is just down the line...

Thomas delivers Jack the Front Loader to a construction site where a team of vehicles from the Sodor Construction Company - "The Pack" is working under the supervision of Miss Jenny. But Jack gets too excited about working and runs into a right spot of bother and Miss. Jenny wonders if he is not ready to join.

Ned the Steam Shovel accidentally knocks loose the important keystones from an old rail bridge, and Thomas is just down the line. Jack, however, with a bright idea, jumps in...

It's Christmas and Thomas and Toby have to deliver a Christmas tree to one of the villages on Thomas' branch line. However the snow is getting deeper and deeper, and when Thomas' snowplough breaks, will the special train make it to the village?

Donald and Douglas have an argument and refuse to speak to or work with each other. However when Donald comes off the tracks, only one engine can come and help him...

Diesel is back after Henry has an accident, and annoys the other engines by boasting about how he is the world's strongest engine. To prove it, Diesel tries to pull 20 trucks at once, but they all have their brakes on and cause a coupling to break resulting in Diesel being launched down the yard...

On Halloween, Edward tells the engines spooky ghost stories. The stories make Percy scared and so Thomas teases him about this. On the same night, Thomas, Percy and Duck are sent to the Smelter Yard. But when Thomas says he can manage alone to finish off the job, off Percy and Duck go, but how brave is Thomas when he's on his own?

Percy goes to collect some goods at the Abandoned Mine, and sees an old chimney there sink to the ground. Percy is spooked, and hears from Donald and Douglas the next morning that the "naughty gnomes" are responsible...

Percy hates being a "middle engine" where he has trucks both in front and behind him. 'Arry and Bert, the Smelter Yard diesels, trick him into being a middle engine, and James boasts at the shed to the others that the pair wouldn't be able able to trick him. They do however and James, annoyed at being a middle engine, refuses to move...

A red hot air balloon has arrived on the Island of Sodor and Thomas is sent to fetch it. The balloon becomes a popular tourist attraction, but James worries it will take his passengers away.

The weather is getting colder so the Fat Controller asks James and Percy to make extra coal deliveries. Thomas seemingly warns Percy that he should be careful or else scary Jack Frost will get him. James thinks this is a load of nonsense, but Percy believes him. But when night comes and Percy has to make a delivery of coal to Lower Suddery both he and then later James think differently, but not as you would probably expect!

Gordon says that pulling trucks "wouldn't be dignified" and Salty teases him about this and acting "too big for his buffers". Gordon becomes cross and wants to show Salty a thing or two but ends up in a rather "undignified" situation instead!

There is a water shortage on the Island of Sodor and Percy is upset because he can't be washed down as often as he would like. He gets very dirty very quickly and so decides to deliver some sugar to the Chocolate Factory - after all, he can't get dirty doing that, can he? But an oil spillage on the track leading straight to the Chocolate Factory spells disaster - and dirtiness!

When Ben gets new buffers fitted, Bill gets jealous. Mavis advises him to forget about it, but Bill becomes so obsessed with it that he loses focus on his own work and has an accident.

Snow has arrived on the Island of Sodor, but for a farmer this has caused trouble. His lambs are trapped on the hills and only Toby can help him rescue them.

An opera singer, Alicia Botti, has been invited to the Island of Sodor and Thomas is to take her to her concert. He is cleaned up ready for the journey, but when boarding Annie, Alicia discovers a mouse onboard!

Thomas is sent to the harbour to pick up a jet engine, but when Cranky accidentally turns the switch on with his arm, Thomas finds himself whizzing down the line!

Gordon comments that "Edward is a useless old steam-pot" and that he should retire. The other big engines agree with him but Percy gets upset at this and tells the Fat Controller. In the end, Edward proves to be a Very Useful engine indeed when Duck and Gordon have a spot of bother...

Duncan is so hasty that he is not uncoupled and goes up the incline with the trucks, but the coupling on the truck his coupling is tangled up with can't hold his weight. It snaps, and down Duncan goes, and there's a muddy pond waiting beyond...

Faced with the threat of forever working in the quarry if their line is not repaired, Skarloey and Rheneas get worried. Rusty though, is onhand, along with the help of Elizabeth, after persuading her that is! Will the line be able to be repaired in the 2 week time limit the Fat Controller has allowed?

Duncan shows off his whistle, and blows it so hard that it shoots into the sky and lands in a field. Duncan's driver says they don't have time to find it, but they need a whistle for safety reasons though. Luckily a school headmaster has an organ they can use as a whistle, much to Duncan's horror.