Polly and Jez are as close as two friends can be - but they've never met. Instead they write letters and postcards to each other.
It's the summer holidays and Polly is setting off on an adventure around Australia. She'll be travelling in a caravan with her grandparents.
Jez is staying at home. She can only read about all the exciting things Polly is seeing - but she has a very good imagination . . .