The Adventures of Jimini and Jacko follows the escapades of two mischievous (and make-believe) little boys who climb aboard a rocket to visit their grandparents in Wales. Once there, they embark on a series of colourful adventures – whether it's on the farm, at the zoo, down the sewers or underground in a disused mine – and become firm friends with a variety of animals as they go. Their travels even take them to the North Pole, where a sleigh ride with a lively young polar bear awaits. Needless to say they get into a number of narrow scrapes, when a plate of Nanny's famous Welshcakes is almost certain to come to the rescue!