For fans of Scandinavian crime novels: When the sawmill owner Mäkelä suddenly becomes friendly to everyone, something must be wrong. The Blueberry Detectives Samu, Alma, Selma, and Olli are convinced of this. Mäkelä is known far and wide as the biggest grouch around. He’s the kind of person who doesn’t do anything for free—not even smile. Clearly, he has something sinister planned, and the detectives soon find out what it is: He wants to cut down an ancient protected oak forest. Allegedly, the trees are infested with a dangerous bark beetle. But why is he ordering exactly those beetles from the internet? Because he wants to release them, that's why! That’s his plan, but the Blueberry Detectives have a better one. They will swap the beetles for mosquitoes and chicken fleas. They don’t care about oaks—but they do care about people sneaking around in the woods at night!.