When the Fat Controller is taken ill, his mother, Dowager Hatt, steps in to run the railway and discovers just how tricky it can be. Luckily, Emily is on hand to help her out.
The Fat Controller installs a swanky new public-address system, but he doesn't know that it isn't working properly and he ends up sending quarry workers to beach, holidaymakers to the quarry and pigs to Callan Castle.
Thinking he is about to be replaced, Cranky works harder. But the harder he works, the more mistakes he makes. Now, he is sure that his days at Brendam Docks are numbered.
Terence fails to take his own advice about being sensible and staying safe when he ventures across a frozen pond to collect a Christmas tree. It's not long before the ice is cracking and Terence is put in great danger.
Gordon and Spencer's rivalry results in their coaches being mixed up and their passengers being upset. Can a new year mark a new start for the pompous pair?
The steam engines are put out of action during a big freeze due to a coal delivery being delayed. While they are waiting, the diesels are put to work keeping the railway running smoothly.