Jack, Rex, and the Lady visit the zoo. But when Jack gets hungry, he sneaks into a koala's cage to steal some snacks. In a case of mistaken identity, the Lady takes the koala home and leaves Jack stuck in the cage. How will Jack escape, and will the Lady and Rex be happier with the new Jack? Welcome to the laugh-out-loud and irreverent world of Jack, a new early reader series by the New York Times bestselling and award-winning team of Mac Barnett and Greg Pizzoli.