In south-eastern Skåne—not far from the sea there is an old castle called Glimminge. It is a big and substantial stone house; and can be seen over the plain for miles around. It is not more than four stories high; but it is so that an ordinary , which stands on the same estate, looks like a little children's playhouse in comparison.  
The big stone house has such thick ceilings and partitions that there is scarcely room in its interior for anything but the thick walls. The stairs are narrow, the entrances small; and the rooms few. That the walls might retain their strength, there are only the fewest number of windows in the upper stories, and none at all are found in the lower ones. In the old war times, the people were just as glad that they could shut themselves up in a strong and massive house like this, as one is nowadays to be able to creep into furs in a snapping cold winter. But when the time of peace came, they did not care to live in the dark and cold stone halls of the old castle any longer. They have long since the big Glimminge castle, and moved into places where the light and air can .
 
At the time when Nils Holgersson wandered around with the wild geese, there were no human beings in Glimminge castle; but for all that, it was not without inhabitants. Every summer there lived a couple in a large nest on the roof. In a nest in the lived a pair of gray ; in the secret passages hung bats; in the kitchen oven lived an old cat; and down in the cellar there were hundreds of old black rats.
 
Rats are not held in very high by other animals; but the black rats at Glimminge castle were an exception. They were always mentioned with respect, because they had shown great valour in battle with their enemies; and much endurance under the great misfortunes which had befallen their kind. They belong to a rat-folk who, at one time, had been very numerous and powerful, but who were now dying out. During a long period of time, the black rats owned Skåne and the whole country. They were found in every cellar; in every attic; in and cowhouses and barns; in and flour-mills; in churches and castles; in every man-constructed building. But now they were from all this—and were almost . Only in one and another old and place could one run across a few of them; and nowhere were they to be found in such large numbers as in Glimminge castle.
 
When an animal folk die out, it is generally the human kind who are the cause of it; but that was not the case in this instance. The people had certainly struggled with the black rats, but they had not been able to do them any harm worth mentioning. Those who had conquered them were an animal folk of their own kind, who were called gray rats.
 
These gray rats had not lived in the land since time immemorial, like the black rats, but from a couple of poor immigrants who landed in Malmö from a Libyan about a hundred years ago. They were homeless, starved-out who stuck close to the harbour, swam among the piles under the bridges, and ate refuse that was thrown in............