The Apollo 11 moon landing on 21 July 1969 has been the subject of many conspiracy theories. The play, based on a children's book by Torben Kuhlmann, retells the story by claiming that the first person to set foot on the moon was not Neil Armstrong, but a mouse named Armstrong, something that the American authorities have tried to hide from all humanity. In the performances at the Man, doll! The Bremen Puppet Theatre, the mouse was represented by a puppet, while the role of the mechanic Mitch was played by an actor.

Mouse Armstrong and his friend, the mechanic Mitch, are listening to a radio special about mankind's first moon landing. Mouse regrets that no one knows the truth: she was the first person to go to the moon, but the authorities named the human astronaut after him. To make it clear how she achieved this feat, she re-enacts the events with objects made for the purpose. We learn that Armstrong did research in Washington, where she was greeted by an old mouse who said that the history of mouse flying was ancient. Armstrong manages to get into space despite having her rocket plans stolen by a secret police agent, and ends up proving to the mice that the Moon, contrary to their belief, is not cheese.