Sune and his family discovers an old painting that could be worth a fortune. There's only one problem, it lacks a signature. Follow the Anderssons in a wacky roadtrip through Europe, filled with crazy fun.

The sleepy little town Valleby is getting ready for the cafe owners Dino Panini's and Sara Bernard's wedding, and our popular young detectives Lasse and Maja stand ready to ensure that nothing will go wrong. But when the wedding couple's respective relatives arrive, they prove to belong to rival mafia families.