TV presenter Markus Lanz invites prominent guests and experts from all areas of public life to his colourful talk show. As a rule, there are four guests, introduced individually to contribute their personal experiences to the topics.

Each 30 minute episode is dedicated to a separate issue or theme and consists mainly of related short featurettes, which explain, explore and educate how things of everyday life and even complex systems work. It spans a wide variety of topics from technology and industry to something as mundane as how the postal service works.

In the late 1970s the German secret service fights against RAF terrorism and searches for constitutional enemies in the public service. Teacher Brasch implicates secret service agent Körner and the government in the suicide of a young teen. As a result Brasch and the exposed Körner are fired.