Thomas and the Bad Dog is a peep through book.
While Thomas was waiting at the station his driver notice in the newspaper that there is a stray dog chasing sheep in the valley. As he was going along the line, his driver noticed the stray dog bothering the sheep as they came out from the bushes and onto the line. Thomas blew steam at the dog and was frightened away, but the sheep were still on the line. The farmer came to round the sheep, but they were so frightened that it took him a very long to clear them away from the line. This made Thomas very late and when he tried to start he found that he couldn't. The guard went back to warn the signalman that Thomas is still blocking the line. Soon Thomas was mended and he made his way towards the next station in a hurry. When he arrived he dropped off his passengers and he waited for the guard to blow his whistle and wave his green flag. But there was no guard to whistle or wave the green flag. It turns out that they've left him behind. Thomas felt terrible and thought it was a bad journey. But his driver and the Fat Controller were pleased with him scaring the stray dog. It made him happy and he forgot all about being late.
- The story is based off the 1989 annual story The Trouble with Sheep.
- In the sixth illustration, Thomas' wheels are coloured grey instead of blue.
- In the tenth illustration, Percy's wheels are coloured grey instead of green and in addition, Annie's face is on the wrong side.
- James' wheel arch and tender lining is yellow and his number is Red with yellow outline, and in addition, James is missing his whistle, handrails and Firebox stripes.
- All of the engines are missing their brake pipes.
- Percy's siderods are not properly drawn.
- Bertie doesn't have any eyebrows.