During their training to become monster agents Nelly and Valle have been told that gnomes and goblins only exist in people’s imaginations. In this adventure they get the chance to find out if that’s true – or if the old folks at Kulturgården are right when they claim that it’s gnomes who are stealing and messing everything up at the retirement home.

Nelly and Valle are visiting Valle’s great grandpa Gunnar who lives at Kulturgården, a popular retirement home with a beautiful garden and stimulating activities for its elderly residents. But Nelly and Valle have hardly set their foot inside before they notice that not all is quite as it should be. The garden is overgrown, dishes are piling up in the kitchen, there are cobwebs in the windows, and the manager of the home seems tired and grumpy. And worst of all, the residents just sit sleeping in their armchairs the short time they are up during the day. Even great grandpa Gunnar, who was always so energetic…

Is all this because of the gnomes? They are said to be behind all the thefts of round items as of late, at least. Or is it someone else responsible all this unhappiness? Nelly and Valle realize that they must fine-comb each and every part of the house to discover if there are small folk afoot, and discover what the manager is really up to.