Heather is a pig whose best friend is a girl called Isla. They all live on a farm in Scotland until a thunderstorm destroys everything and forces Isla's dad to sell up and move to London – leaving Isla and Heather miles apart and utterly miserable. Then fate intervenes, turning Heather into a national celebrity, and catapulting her to fame, fortune and, most excitingly of all ... London. Armed only with her own pig-headedness, Heather embarks on a quest to track down Isla. After all, how many girls with freckles can there be in London?