Big Catch is a magazine story.
The Fat Controller takes his grandson Stephen on a fishing trip, and they make a bet to see who catches the larger fish. Meanwhile, Percy is on his way to the Market with a trainload of fish. The trucks don't enjoy carrying fish, so they bump and bounce around. When Percy passes the Fat Controller, they see him and behave again. Later that day the Fat Controller and Stephen are disappointed because they aren't catching much, and decide to head home. Percy passes again as they get to the car park, and this time the trucks don't see the Fat Controller. They start misbehaving again, and causes a box of fish to break open. A fish flies into the air and lands in Stephen's arms. It seems as if he's caught the biggest fish after all!