A down-on-his-luck detective is charged with the search for two orphaned runaways. The two brothers, Prosper and Bo, are hiding in Venice, sheltered by a colourful gang of street children led by the amazing and charismatic Thief Lord, a petty-criminal mastermind.
Together they enjoy an exciting game of pursuit and easy pickings, outwitting the plodding detective and every turn. But then the Thief Lord, a boy himself, decides to accept a bigger challenge - to steal a forgotten treasure. He unwittingly leads the gang into a dangerous, adult world that leads back to a magical carousel that can stop time.