Edinburgh, 1874. Born with a frozen heart, Jack is near dead when his mother abandons him to the care of Dr. Madeleine—witch doctor, midwife, protector of orphans—who saves Jack by placing a cuckoo clock in his chest. It is in her orphanage that Jack grows up, amid tear-filled flasks, eggs containing memories, and a man with a musical spine. Dr. Madeleine warns Jack that his heart is too fragile for strong emotions: he must never, ever fall in love. But of course, he does, on his tenth birthday, and with head-over-heels abandon, for a bespectacled young street performer with a soul-stirring voice. But it's not only Jack's heart that's at risk, it's his very life. Now begins a wild journey of escape and pursuit, from Edinburgh to Paris to Andalusia, where Jack will finally learn the great joys—and the greater costs—of owning a fully formed heart.