When Henry and his big dog Mudge see a spy kit for sale, they know right away that it's time to break open the piggy bank. With their spy hat and magnifying glass and secret code card, Henry and Mudge can flirt with danger, steal secrets, and start cracking codes. On their first spy mission, Henry tells Mudge to try not to look suspicious. Mudge rolls in the mud and chews on an old shoe, so no one will ever think he's a spy. But then Henry finds a...