Porridge the Tartan Cat (it's a long story involving a tin of tartan paint!) has discovered Gadget Grandad is not your average snoringly boring grandad after all! He's a super-duper secret spy — and he needs help from Porridge (the cat, not the gloopy breakfast) and the twins Isla and Ross to defeat his arch enemy Fergus McFungus. McFungus has stolen the secret secret recipe for disaster. Can Porridge and the twins help their shark-surfing, shed-racing, space travelling grandad stop him and save the world? Maybe with the help of some brawsome bagpipes...