Giuseppe is an orphaned street musician who sees no way to escape from his ruthless master, until the day he finds an enchanted green violin.

Frederick is an apprentice clockmaker with a past he cannot remember, who secretly works to build the most magnificent clockwork man the world has ever seen.

Hannah is a maid in a grand hotel, whose life is one of endless drudgery, until she encounters a mystifying new guest and learns of a hidden treasure.

As mysterious circumstances bring them together, the lives of these three children soon interlock, like the turning gears of a clock, and they realize that each one holds the key to the others’ puzzles. The trio’s adventures sweep them through the winding alleyways and glittering plazas of their city, and along the way Giuseppe, Hannah, and Frederick must learn to trust in one another — and in themselves — for they risk losing the things they hold most dear, as the dangers they face quickly become all too real.