The Svein, Dan and Melissa are chocked witnesses as Grandmother is placed in an institution where old and frail people dies like flies. They try to lighten her moods, but she turns more and more senile. Svein's rat, Halvorsen, displays many of the same symptoms, and the children are convinced there is foul play involved. They discover that aliens roam around, seeking knowledge. And where is knowledge better kept than in the souls of old people? To prevent the aliens from sucking Grandmother's soul dry, Svein, Dan and Melissa comes up with a cunning plan...
—Ragnhild