Väinö Weckström

Maria and Aste are happy, fun-loving girls with lovely parents and a happy family. But by chance, the parents end up planning a divorce, and the father moves into a small studio apartment that turns into a pigsty in a week. Both parents end up in the same restaurant on the same night for a date with their new partners, and the girls hatch a plan to bring the family back together that same evening...

Henkka Virtanen finds evidence of a possible crime on his way to school. With his friend J.K. Kivimutka, the boys decide to investigate what has happened, because these criminal cases are the responsibility of the detective agency they have set up. When it turns out that mailboxes in the area have disappeared during the night, the detective bureau has already two crimes to solve. A fun and exciting adventure begins, in which the boys also have to face their own fears.