Purdy the cat and Barker the dog live together in a sky-blue house on top of a hill.
Barker likes the garden. He wants only to dig, to scratch up the earth and turn it over. But Purdy has big dreams: he wants to fly south with the birds, win the singing competition, be a Supercat.
One day Purdy decides that if he could just get a bicycle and ride it to the moon, he would be the happiest cat in the world, and never want anything else again. Ever.