Gramps is going to visit his old friend Zeus at their favourite childhood theme park, and the gang tags along for the ride. However, while getting there is half the fun, the kids' antics cause the van to break down! Can they work together to get Gramps to his friend before the park closes forever?

Cat becomes superhero Cat Crusader again, but a jealous Gherkin frames her into looking like a bad cat rather than a hero. The gang has a plan: Mouse will go undercover as a super-villain and restore Cat's good name and confidence. What could possibly go wrong?