The Lying Postman

Postmen always rattle letterboxes.
Dogs bark when postmen rattle.
Postmen yell when dogs bark.
That’s how you play the postman game.
This is a fact.
There’s a new postman in Doggeroo — and he doesn’t know
the rules of the Postman Game. Not only does he accuse Foxie
of biting him, but also he calls Jack a mongrel! And when Fat
Molly Cat from the library comes to stay with Aunty Tidge,
things don’t get any better. What did Jack find caught on the
fence? Will it help him solve the case of — the lying postman?