In an attempt to set a good example for his family, Moominpappa becomes a changed Moomin when he decides to get a job. But all is not what it seems.

When Moomintroll gets his wish to be free of the troublesome Little My, he soon comes to regret it.

When Moominmamma is accused of an unlikely crime, Moomintroll turns detective to try to save her. Can he succeed where his father couldn't.