Black-tie spy

de George Glass

"Titus Coin is about to become the richest kid in the world. He's inheriting the fortune of his last grandfather, including a priceless gemstone, the Blue Carbuncle. To celebrate, Titus is throwing a fancy black-tie party for kids only. But the Blue Carbuncle has a secret, and Spy Academy needs to find out what that is." --From publisher description.