On the coldest day in the history of the world, little Jack is born with his heart frozen solid. Wasting no time, midwife Madeleine takes action and saves his life by inserting a cuckoo-clock in place of his icy heart. Now Jack will live…as long as he observes three golden rules: He must never touch the hands of the clock; He must master his anger; He must never, ever fall in love.

But fall in love he does, to a bespectacled young street performer, Miss Acacia, with a soul-stirring voice. Next begins a journey of escape and pursuit, from Edinburgh to Paris to Andalusia. Jack finally learns the great joys, and ultimately the greater costs, of owning a fully formed heart.