Svein and the hooded rat Halvorsen go on a summer vacation in the country together with their friends Dan and Melissa, and the rats James Bond and Pippi. The cool summer vacation with late summer nights and Grandma's telescope, hot chocolate and lots of sweets, seems to go down the drain, because Grandma is ill. The children are shocked when they witness Grandma being placed in an old peoples' home, where the oldies die like flies. As Halvorsen starts to show the same symptoms as Grandma, the kids are convinced creepy stuff is happening at the old people's home. After thorough investigation, it turns out the old people's home is housing extraterrestial aliens hunting for knowledge. To prevent Grandma's soul from being stolen by aliens, the children kidnap her, and escapes into the woods.