Trilby's best friend Polly Possum is moving away. B. Max has an imaginary friend, Professor Fluffy.
Trilby's best friend, Polly Possum, is moving away, so the dogs explore ways to keep in touch with a friend. Together they make friendship presents. When B. Max introduces everybody to his imaginary friend, Professor Fluffy, the others decide to use their imagination and pretend they have friends like this, too.