At the end of the 1950s, the production of optics in the German Democratic Republic has reached top quality and instigates interest in the West. When national demand rises strongly and at the same time the export to South America heavily decreases, the Volkspolizei - the GDR police force - starts to look into the case. Two seemingly unrelated cases are the starting point for the investigation by second lieutenant Schellenberg of the department for optics racketeering: An old woman who was arrested in the Berlin city railway for trying to smuggle a pair of binoculars to West Berlin, and a dead person in an area of allotments who was involved in obscure dealings with optical devices.

When Prince Vain got his shirt fixed, he proclaims that he had slain two lizards in front of the tailor's house - "two in one strike". When the tailor swats seven flies at once, he sows himself a banner saying "seven in one strike", and together with his bird he starts a journey into the world to pronounce his deed.

This film is set in a medieval mill town in the Harz mountains. The greedy and brutal millman and his accomplices, the castle steward and the mayor, set fire to a forest mill that the farmers used for processing their grain. Without their mill, the farmers must now rely on the millman's services. When the farmhand Anna uncovers the millman’s crimes, he swiftly detains her and a young miller, Jörg. The forest spirits have a different plan, however, and they free the young couple with the charge to rebuild the ruined forest mill and turn things around for the villagers.