"The city of Trolberg has yet more secrets to unravel in an adventure where Hilda discovers her world is not quite held together in the way she thought it was. Hilda is sat in her tent, dwarfed by volumes of the Greater Fjords Wildlife Chronicles with a flashlight and her restless companion, Twig. But Hilda's not in the Fjords and it isn't raining. Hilda's pitched a tent in her room and it's been days since she's been out. In Hilda's new adventure, she meets the Nisse: a mischievous but charismatic bunch of misfits who occupy a world beside -- but, also somehow within -- our own and where the rules of physics don't quite match up. Meanwhile, on the streets of Trolberg, a dark specter looms ..."--Provided by publisher.