Holger Nilsson is forced on a raging treasure hunt to find the seven keys to his world-famous relative Mary Diana Graaf's mythical laboratory. To help him, he has the inventor Mortensen and Mary Diana's GPS computer with pre-recorded riddles and clues written in verse. But what kind of mysterious and malevolent figure lurks in the background?

The friends Alexandra, Edvin, Dushan and Tindra have graduated from the sixth grade and are looking forward to a long summer holiday with lots of swimming and adventure. Tindra's birthday is to be celebrated and the friends have big plans. But in each direction they all go through different difficulties and nothing turns out as they have imagined. Instead, the holiday looks like it will be a total disaster. Summer before seven is a continuation of Summer before six and is about friendship, love, empathy and courage.

It's summer vacation. A summer vacation that brings together twelve-year-olds Alexandra, Dushan, Tindra and Edvin. Usually they hang out with completely different friends. But now it is only those who are not gone and the four agree on a revenge against the mythical Foil Man. His windows are covered with foil and rumor has it that he kills cats, puts them in the freezer and buries them in an animal cemetery in the woods.