Princess Daniela is grumpy and never laughs, and her father promises a beautiful glass palace to the man who can make her laugh.

The best glassmakers in the city create a swirling tower of a palace, and men come from far and wide to try their luck in amusing Princess Daniela. But Maestro Filippino with his swords and snakes, and Signore Guisepe with his growling carved tiger and Professore Alchemista with his secret potions cannot raise a smile from the princess.

It is only when young Angelo pulls a molten goblet out of the fire, splits it and spreads it with slivers of silvery mercury to create a secret object that the princess breaks into a smile.

She sees a funny creature in the glass - which is in fact her reflection. Angelo has made the very first looking glass. The glass palace splinters to smithereens from the sound of Daniela's laughter, and the whole of Venice rejoices.