The War of the Five Kings, once thought to be drawing to a close, is instead entering a new and more chaotic phase. Westeros is on the brink of collapse, and many are seizing what they can while the realm implodes, like a corpse making a feast for crows.

In Scotland 1874, Jack is born on the coldest day ever. Because of the extreme cold, his heart stops beating. The responsible midwife in Edinburgh finds a way to save him by replacing his heart with a clock. So he lives and remains under the midwife's protective care. But he must not get angry or excited because that endangers his life by causing his clock to stop working. Worse than that, when he grows up, he has to face the fact he cannot fall in love because that too could stop his delicate heart.

Orphaned and alone except for an uncle, Hugo Cabret lives in the walls of a train station in 1930s Paris. Hugo's job is to oil and maintain the station's clocks, but to him, his more important task is to protect a broken automaton and notebook left to him by his late father. Accompanied by the goddaughter of an embittered toy merchant, Hugo embarks on a quest to solve the mystery of the automaton and find a place he can call home.