- “What's the matter, Percy?"
"Nothing exciting ever happens, that's the matter.
It's just coal, coal, coal and trucks, trucks, trucks!/cars, cars, cars! I'm bored, bored, bored!”
- ―Percy complaining to Bertie
A Surprise for Percy, retitled A Big Surprise for Percy in most American releases, is the twenty-first episode of the fifth season. It aired during the second airing of Storytime with Thomas in the US.
Percy has been working at the coal mines for several weeks and is fed up with the work. Toby and Bertie try to cheer him up, to no avail. Then one day, Percy is pulling some trucks up to the yard, when they break away. Percy and Bertie chase after them and Workmen manage to put chocks under the trucks' wheels after they slow down going up a hill. After that, Percy decides that one should never be taken by surprise.
- Sir Topham Hatt
- Henrietta (cameo)
- Jeremiah Jobling (cameo)
- Farmer Trotter (cameo)
- Thomas (deleted scene)
- Stock footage from Put Upon Percy is used.
- This is the only episode in the fifth season to have different titles in the UK and the US.
- When the trucks first sing, music is used in the US and international versions but not in the UK version.
- Much of the footage during the runaway is sped up.
- The load that Cranky drops on Percy from Cranky Bugs is seen on the ground to the right of the screen when the trucks at the coal mine sing.
- This marks the only appearance of the Miner's Halt station in the television series to date.
- The backdrop is visible during a close-up of Percy struggling up the hill.
- Just before the truck's coupling breaks, Percy's piston appears to be broken.
- In the bird's-eye shot of the trucks, a wire can be seen pulling the trucks forward.
- In some shots of Percy pulling the trucks up the hill, his first red stripe is out of place.
- The mine at the coal yards appears to be active, but the mine shaft collapsed in Put Upon Percy.
- In one scene Sir Topham Hatt and Bertie park at the end of the stone wall, but in the next scene they are nowhere to be seen.
- Throughout the runaway, Bertie is smiling.
- In a close-up of the trucks racing up the hill, the brake van is at the wrong end of the train.
- Shortly after the chase begins, Bertie has stopped at the far end of the set.
- When this episode aired on Storytime with Thomas, the UK title was used.
- When Percy goes in between the two lines of trucks, the first truck on the viewer's right is coming off its wheel frames.
- When the narrator says "The trucks were still grumbling," the first truck in line's left (viewer's perspective right) buffer is missing.