In a calm and sleepy summer Oslo, a murder was committed - daring and defiant. The culprit left the police not only the crime weapon, but also a small diamond in the shape of a five-pointed star, hiding it under the eyelid of the deceased. Soon the Norwegian capital is shaken by a series of mysterious events mystically connected with the number five: the five rays of a star and a mutilated palm persistently remind us of it. Every fifth day, the police find a new victim of a mysterious criminal, who each time manages to escape unnoticed.