When their fifth-grade class spends a weekend interning at the state capital, Dunc and Amos find themselves face-to-face with Amos's walking doubleGustav, Crown Prince of Moldavia! His Royal Highness is desperate to uncover a traitor in his ranks. And when he asks Amos to switch places with him, Dunc holds his breath to see what will happen next. Can Amos pull off the impersonation of a lifetime?