The Prince listens to Rinaldo, though he seems a bit annoyed. He glances over at his advisors and smiles, as the merchant's meaning becomes clear. "Ah. You've spotted Mr. Frump, have you? You are a clever bunch."
He turns to address his aids. "Reveal yourself, Wimpell. These men have spotted you despite your disguise." Smiling broadly, he gestures towards one of his advisors, who has now shed his illusionary disguise. There stands none other than Wimpell Frump, looking terrified, but nicely dressed and well-fed for a change.
"Knights of the realm," says Prince Medius grandly, "I believe you know my new court wizard, Wimpell Frump. He's well qualified, don't you think?"