Polizeiruf 110 is a long-running German language detective television series. The first episode was broadcast 27 June 1971 in the German Democratic Republic, and after the dissolution of Fernsehen der DDR the series was picked up by ARD. It was originally created as a counterpart to the West German series Tatort, and quickly became a public favorite.

On the run from police in America, Antonio Morena, a former World War II aviator and black-marketeer, finds himself in South America working for the all-powerful United Fruit Company, known to the natives as "the Green Monster".

Bundeswehr soldier Klaus’ regiment is stationed in France, to take part in NATO maneuvers. The soldiers are ordered to be kind to the populace, since the West German High Command wishes the French to forget the atrocities that were committed during the Second World War. Klaus falls in love with Jeanne, the daughter of the local mayor. He discovers that his commanders intend to demolish the ruins of a local church, in which civilians were murdered by the German occupation forces at 1944. A local journalist who researches the event discovers that West German General Rucker ordered the massacre, but he is mysteriously murdered. Klaus defies his commanding officer Siebert, who instructs him to steal the documents indicting Rucker, and hands the evidence over to Jeanne.

An American military plane takes six people, who have taken part in a NATO maneuver, from Tripoli to Oslo. Among them are the British Captain Loy and the United States Air Force Corporal Doris Graves. During the flight, the two become closer, and they regret that the trip will end that evening. But everything turns out differently. The flight captain has received orders to pick up an agent at a German NATO airport, who is to be dropped off again on a Soviet island …

In the late 1950s, the collectivization of agriculture is in full swing in the East German village of Willshagen on the German-German border. Those in charge have to face many obstacles, especially from a large-scale farmer who is unwilling to join the co-op. All of a sudden, mysterious men in a fancy car appear in the village and show an interest in the rundown manor house. Gossip spreads quickly, and some villagers think there will be a re-parceling of properties and a land swap with West Germany. They assume everything will go back to how it used to be and even expect the count to return to his manor. In preparation, the situation in the village escalates at a fevered pitch.

Two young building workers are more interested in girls than their work; complications ensue at home.

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.

Railway employee Fritz Marr is not regarded well by his superiors. It is the year 1920, and trains regularly pass the railway hub of Erfurt to the East to secretly transport weapons for the fight against the young Soviet Union. Marr knows about this and wants to mobilise other workers to stop these illegal deliveries. To muzzle him, Marr is relocated to a remote rail work construction site.