Never heard of old man Pettersson? Then it is high time! Old Pettersson, who lives on a small farm together with tomcat Findus, can not only bake birthday cake and make fireworks, sometimes he can also be in a very bad mood. In autumn, for example, when it is damp and cold outside. Like a car tire running out of air, he then sits in the corner of the sofa, feeling sorry for himself and wanting nothing but to be left alone. But that's not what Findus has in mind. What Findus is up to and how he turns the grouchy one back into a cheerful Pettersson, that's what this funny picture book tells us.