The action takes place in late communist Poland and in a fictional Lilliputian kingdom called Szuflandia (Drawerland), hidden deep underground the Quaternary Research Institute.
Kingsajz used highly oversized props and sets, supervised by production designer Janusz Sosnowski, intended to capture the difference in size between the little people and the large things from the above ground world that they use.
As of 2024, some of the largest surviving props from the film (such as a giant telephone, a gigantic lady's shoe, a car-sized iron teapot used in the krasnoludki land of Szuflandia / Drawerland, gate-sized kitchen utensils, and more) are displayed outside the Museum of Cinematography in Łódź.
While hiding in Kingsajz he works in his secret laboratory to discover the potion formula, hoping to be able to manufacture it one day and give it to all the gnomes in Drawerland.
The movie starts when Adaś finally discovers the secret and has to immediately escape from his lab which is being demolished by human sized gnome agents that tracked him down.
When Olo gets there alone and liliput-sized he allows himself to be captured and manages to fool Drawerland's high officials that he is in fact a secret agent working on Adaś's case.
After that Olo manages to escape from Drawerland, but the vial with Kingsajz which Adaś gave Ala earlier gets smashed, so although he is free, he remains gnome-sized.
Soon Adaś uses telepathy once more to call for help as Drawerland official decipheres his message too, accuses him of treason and the rebel scientist is about to be executed.