Wilson and Brewster are sent to get stone from the mountain quarry. Brewster is in a hurry to get the job done, and doesn't hear Dunbar warning them to be extra careful on the way back, as going downhill with a heavier load is harder!
The trainees are heading for a lesson with Dunbar in the training yard when an underground tunnel catches Koko's eye. She wants to explore it but Vee says she isn't ready yet. When no one is looking, Koko decides she's going to see where that tunnel goes...
Eddie lives so far away from Chuggington that he just can't seem to get into work on time. After he gets into trouble with Morgan yet again, Hodge and the trainees set out to find a new home for Eddie in Chuggington.
The trainees are learning how to use ice-cream cars, and the great Frostini is going to test them on their skills. When Wilson's car breaks down, Puffer Pete comes to the rescue, pulling out his old steam-driven ice-cream wagon.
Part of the track is out and there is chaos in Chuggington! Vee needs Eddie to repair the track but he is late for work again. As Hodge prepares the magnetic crane, Wilson persuades him to do the repairs by himself.
it is time for the annual Chugger Championship Race, and Koko is sure she can win. She spends hours practising and ends up arguing with Wilson. When Wilson breaks down during the race, Koko must choose whether to help him, or keep going and win.
Koko is yearning for adventure and she just might get it, as today the chuggers are making deliveries out of town. Vee asks old Puffer Pete to join them and, during their travels, they come across a mysterious old track that leads to Old Chuggington, which is now a ghost town.
The chuggers learn how to carry passengers comfortably using dummies specially made to wobble if the ride isn't smooth. When poor Wilson struggles to drive smoothly, Eddie has an idea that just might help him.
Brewster is excited about seeing the new Action Chugger movie, but Irving sends him to the foundry and Brewster worries he won't be back in time for the film unless he can be as speedy as his super chugger hero.
Olwin takes Brewster, Wilson and Koko on an outward-bound training course but when she treats them like babies, they hide in the Old Town. It is all fun and games until a heavy fog rolls in and the trainees realise they are trapped.
A storm has left the safari park in a bit of chaos and some of the animals have escaped. Emery teases Brewster, saying one of the escapees is a dragon. The Chuggers don't believe him, but when they hear a mighty roar coming from one of the tunnels, they start to think he might be right.
The trainees are doing a sign-reading exercise and they are promised a wonderful surprise at the end. Koko and Wilson think Brewster is too slow, but Brewster's patience pays off when he meets his hero Action Chugger at the ride-in movie theatre.
Wilson is asked to take refrigerated cars to the ice-cream fair, but when his hero Frostini offers him a tour of the ice-cream factory, he forgets all about the important job he's supposed to be doing.
Mtambo is training Wilson and Brewster to help out as guides at the safari park. He tells them to pay close attention to what he tells them about the animals but, as usual, Wilson is impatient and slips away to take some children on a tour.
The trainees must learn how to make difficult emergency stops with mud, leaves and water on the rails. Wilson loves getting dirty but he'll do anything he can to avoid going through the automatic chugwash!
Wilson is helping Frostini as he creates a new flavour of ice cream for the mayor's banquet. When they discover the mayor's wife is allergic to cheese, Frostini realises he will have to come up with something else.
The trainees try their wheels at pulling and rolling stock around an obstacle course. Ambitious Wilson tries the fire wagon. The course seems easy - until Dunbar tells them they have to do it backwards.
Calley is doing emergency rescue training with the trainees. If they do well, they will earn a badge. But when Chatsworth gets into trouble in the mountains and Calley is nowhere to be found, Brewster must ride to the rescue.
The trainees are learning to use the paint wagon and Wilson has trouble concentrating. While Koko and Brewster learn how to mix colours, Puffer Pete takes Wilson to the Old Town for some extra painting practice.
Dunbar has a new training device, a voice-operated storm simulator tunnel, which simulates wind, rain and fog. When Dunbar is called away on an emergency, Wilson messes with the controls and the storm maker unleashes a violent storm.
A magazine photographer is coming to Chuggington to do a feature on steam trains, and Olwin is determined to look her best for her picture. But she doesn't notice when a bottle of soap accidentally lands in her water tank.
Vee needs someone to pull the royal carriage for the Prince of Buffertonia and all the Chuggers race to get the job, but Harrison is first - thanks to cutting corners and going through a few red lights!