Frida, it must be said, is rather small. But so are Flii and Mo: Flii is a little rascal, and Mo is a whale, but he never really managed to grow either. So the three of them live together as best friends in their town. This town isn't really big, but what makes it special is that it is surrounded by a wall on all sides. As long as Frida can remember, this wall has been there. And both Frida's mother and her grandmother say, "As long as I can remember, this wall has been here." Flii complains loudly, "Look at how you live! No one goes out. No one comes in!" And Frida also finds all of this very unfortunate. Doesn't anyone want to know what is behind this wall? The curiosity of the three friends cannot be stopped by anything, not even by the tallest wall.