As Dad arrives home with a mystery package, he finds himself set upon by three pirates: Biff, Chip and Kipper. They have their eyes set on the large box packaging, which they think will be perfect to make their very own pirate ship in the garden. But, as their piratical creation takes shape, Wilf and Wilma spy on them from next door and are quickly inspired to make their own pirate ship too. On either side of the fence, the children’s swashbuckling creations soon become larger and more colourful as they each compete to see whose ship will be the best.