Summer is coming and the engines are looking forward to taking vacationers around Sodor. One day, Sir Topham Hatt announces that an airport is to be built on Sodor, which will bring more vacationers than ever. Thomas and Percy go to the site of the new airport, only to discover that 'Arry and Bert are on the same job.
That afternoon, Thomas goes to the timber yard and finds 'Arry and Bert there. They boast that their job is very important, but Thomas doesn't think so and biffs their flatbeds just before the crane drops the timber. Whilst Thomas and Percy are shunting freight cars, Diesel confronts Thomas about the trouble he had caused for 'Arry and Bert, and boasts that he too has an important job.
After shunting cars of bananas for Diesel as a prank, Thomas and Percy go to the Smelters to collect some steel girders. Upon arrival, they see Diesel 10 and his huge claw, "Pinchy", and are so scared that they run away. On their way home, Thomas and Percy are surprised to see the Sodor Suspension Bridge is not painted and the new airport is only half-built. Worse still, Tidmouth Sheds have been demolished to make way for the new sheds, but since Thomas gave Diesel cars of bananas the renovation is running late. That night, a gale sweeps across Sodor and causes havoc. The next morning, Sir Topham Hatt tells the engines that the storm damage must be cleared up before the work on the new sheds and the airport can continue.
The next morning, Thomas is sent to collect some new sections for the suspension bridge from Brendam. Upon arrival at the suspension bridge, Thomas feels tired and the beams need to be placed. Diesel wants to do it, but the foreman decides to let Thomas do it. Thomas manages to lower the beams into place, much to Diesel's fury.
When Thomas goes to collect paint for the bridge, Diesel biffs Thomas's flatbed so hard that paint cans splash all over Thomas. When Thomas sees 'Arry, he biffs him into a pile of gravel. In retaliation, 'Arry biffs James under the coal hopper, Gordon biffs Bert under a flour chute, Diesel biffs Toby onto the tippers loading ramp which tips him upside down, Emily biffs Diesel through a shed, Bert bangs Henry under a chute that spills treacle all over him, and Henry biffs Diesel through some buffers and into a marsh. The matter escalates until all the engines are fighting violently. By the end of the day, everyone is dirty and no work has been done.
Sir Topham Hatt is cross at the delays and warns the engines that anymore disturbances will make the railroad close. That night, Thomas has a dream on how to make things better. In the dream, he sees Lady and Rusty working together. Lady tells Thomas about teamwork and Thomas goes off to find Mavis as soon as he wakes up.
Thomas finds Mavis at the wash-down and tells her about his plan: the Diesels and steam engines must work together to save the new airport and their home. Mavis explains that they must talk to each other first, so Thomas suggests to have a meeting at the coaling plant the next day. Thomas and Mavis tell the engines about the meeting, and Thomas decides to tell Diesel 10, but gets cold wheels and runs away. The next day, Thomas races to the coaling plant and gets there, just to see 'Arry and Bert almost calling the meeting off as the engines start to argue about who is to blame for starting the trouble. Thomas explains that they must work together, and at last the engines put their differences aside. When Harold brings Sir Topham Hatt, Thomas explains they have agreed to work together.
Very soon, the new airport is complete and the first airplane is sent to Sodor, but when Thomas' freight cars come off the rails they hit the water tower, which falls to the ground and cracks the runway. The workmen quickly fix the runway, but they need George to finish the job and with Harvey on the other side of Sodor there is no chance of the airplane landing. Thomas quickly has an idea and rushes off to find Diesel 10. Thomas asks Diesel 10 to help them and tells him that he will be the most useful engine of the day. Diesel 10 agrees and he follows Thomas to the airport. Mavis, Percy, 'Arry and Bert are surprised to see Thomas and Diesel 10 working together. Helping out each other, they clear up the mess and Thomas collects George.
With the runway smooth again, the airplane lands at last. The engines have learnt that teamwork runs a railway, not opposition about their differences. That evening, the engines are happy to see Tidmouth Sheds rebuilt, it has an extra space for Emily too. That night the engines talk about steamies, diesels, and airplanes, and they all agree that Tidmouth Sheds is the best place to be.