Merton isn't happy at the prospects of dozens of dangerous drivers when Aidensfield hosts a prestigious car hill-climb. The villagers aren't happy either, and when a saboteur begins causing chaos, the team face a race against time to identify the culprit and prevent a catastrophic disaster. Meanwhile, Bernie finds an old car in a cowshed and decides to renovate it, giving Vernon his chance to scoop the winnings in the car hill-climb event.