Deep among the Swedish pines lies the fantastical world of the trolls. More often than not, these kindly creatures keep themselves to themselves, but this summer is different. Ten-year-old Poppy's school holidays are transformed when she befriends the young troll Baggledorf at the forest lake near her Grandpa's cottage. Baggledorf is a chunky, hairy, but cuddly individual with a few vile habits, and many exciting hobbies. The fun-loving troll introduces Poppy and her dog, Fred, to quarry cloud racing, deep-forest grass boarding, and pine-tree sliding.