We rejoin our heroine for her latest experience just as she wakes up to discover herself ... in the body of a troll! Her mum is apprehensive, as well as now needs to handle the unusual animal that seems to have actually taken Hilda's place. Now, both of them are in a race to be rejoined before Ahlberg and also his safety patrol get the chance to use their brand-new ace in the hole to lay waste to the trolls, as well as Hilda together with them!