Short summary - The Wonderful Adventures of Nils (Nils Holgerssons underbara resa genom Sverige)
The gnome turns the main character Nils Holgersson into a dwarf, and the boy makes an exciting journey on a goose from Sweden to Lapland and back. On the way to Lapland, he meets a flock of wild geese flying along the Gulf of Bothnia, and with them looks into the remote regions of Scandinavia. As a result, Nils visits all the provinces of Sweden, gets into various adventures and learns a lot about the geography, history and culture of each province of his homeland.
In a small peasant yard in the very south of Sweden, fourteen-year-old Nils Holgersson lives, bringing only trouble to his parents, because he is lazy and angry by nature. One day at the end of March, for another evil trick, the good dwarf who lived in Niels' house turns him into a gnome himself. Gander Martin intends to join a caravan of wild geese that are about to fly to Lapland. Niels is going to prevent this, but nothing comes of it, because he himself is a baby: the gander simply puts him on his back. After Niels helped several animals in trouble, the leader of the pack, the old and wise goose Akki, decides that it is time for Niels to return home to his parents and that he can become a man again. But Niels wants to continue his journey with the geese around Sweden, rather than turning back. Now our hero continues to travel with geese and learns about the nature of his country, its history, culture and cities. At the same time, he is going through many dangerous adventures, during which he will have to make a moral choice.
In parallel, the story of the peasant girl Aza and her little brother Mats is described. They are friends of Niels who often guarded the geese together. Suddenly their mother and all brothers and sisters die. It seems to many that this is the curse of one gypsy. The father of Aza and Mats, out of need, leaves his children and becomes a miner in Malmberg, in northern Sweden. One day, Aza and Mats find out that their mother and brothers and sisters did not die at all from a gypsy curse, but as a result of tuberculosis. They go to their father to tell him about it. During the journey, they learn what tuberculosis is and how to fight it. Aza and Mats soon arrive in Malmberg, where Mats dies in an accident. Having buried her brother, Aza meets her father: now they are together again!
Nils returns with wild geese from Lapland in autumn. Before continuing on his way across the Baltic Sea to Pomerania, the gander Martin drops Niels off in the yard of his parents, who are already worried about the loss of their son. They catch the gander and already want to kill him, but Nils does not allow them to do this, because with Martin they have become true friends. At this point, he turns back into a human.