Christopher Awdry takes us back to the Island of Sodor and reintroduces us to Thomas the Tank Engine and his friends again, with Thomas, Percy and Duck all helping out.
But when Thomas gets above himself, he soon learns how difficult Gordon's work is and tank engines can't do everything!
Thomas and Percy fall out when the pair have incidents with coal, and Thomas's life is made no easier by delays caused by the Main Line engines, and a faulty handbrake causing him to run away down the line on his own!
When a bridge becomes a concern on the Ffarquhar Branch, Thomas is sent to work on Edward's Branch, where he's teased by the cheeky tank engine twins, Bill and Ben.
But when the twins need help and a stronger engine, Thomas comes to their rescue, and they all become friends in the end!
After Henry suffers trouble when he uses some bad coal that's been delivered to the railway, the Fat Controller sends him to the Works to have an overhaul.
But he soon "sees red" while he's sitting in an undercoat and he's recalled to service to help run a train!
The engines of the Skarloey Railway try to keep trains going in spite of slippery rails, Sir Handel playing a naughty trick and Skarloey being held up by pigs near the track as they prepare to welcomes the railway's newest member to the roster - Ivo Hugh.
Sir Handel is invited to Wales to help out on the Talyllyn Railway for a while. He gets so haughty about it, he ends up leaving his Guard behind.
Meanwhile, Peter Sam and Duncan have their own troubles whilst he's away!
Gordon finds himself in a difficult position. First he wears the rails to grooves when he slips on ice, and then thinks he's spoilt the Fat Controller's hat with ash.
Meanwhile, modernity comes to Sodor in the form of Pip and Emma - the High Speed Train!
The Small Engines are in high demand, so much so that the Small Controller decides to build a brand new engine to help out on their railway.
Jock proves a powerful new friend, but Mike and the others make sure he realises that it's teamwork that counts on a railway.
The Fat Controller needs a new engine to help out on the Branch Lines, and knows where to get one, but first - he needs to trial one similar!
Wilbert soon finds himself filling in for Percy on Thomas's Branch Line and encountering all sorts of eventualities that Sodor engines are known for during his visit!
Toby finds himself in need of another coach when Henrietta finds herself much too overcrowded. Luckily, Thomas finds Victoria, an old coach in need of restoration, who is delighted at the prospect of being really useful again!
James takes a dim view of Diesel Engines, which isn't helped by a visiting engine throwing his weight around - and through the back of the shed wall!
That all ends when he's helped by a kindly new friend who lives at the Works, when he breaks down himself.
After Mavis has a run in with a lorry on the way down from the Quarry, Toby has to take her place and do her work as well as his own, and on one particular run, comes off the line himself!.
Down at Knapford Harbour, poor Percy has a run-in with Bustrode the Barge!
Thomas is invited to the National Railway Museum in York, and hits a level crossing gate and receives a parking ticket on the way!
Despite every eventuality, Thomas ends up helping Green Arrow when they encounter trouble on a Rail Tour, and receives Honourary Membership of the National Collection.
The Fat Controller's Engines are celebrating 50 years of the Railway Series with a Golden Jubilee celebration.
Gordon hits a bird, Edward loses a wheel and Thomas's Branch Line is affected by rabbits burrowing under the railway!
In the last ever Railway Series book, Gordon makes way for Pip and Emma to take over as the new Express Engine on the Fat Controller's Railway, and the engines celebrate the Thin Clergyman's 100th Birthday with the unveiling of a bust at the Big Station.