Lyra has stepped into a brand-new world. Will has just killed a man.

Their paths cross in Cittàgazze. In a city haunted by soul-eating Spectres, troops of angels and vengeful witches, they find in each other a welcome ally.

Both are hoping to find something in this strange world: Lyra must discover the meaning of Dark Matter, while Will is desperately searching for his missing father.

What they find instead is a deadly secret, an object with extraordinary power. Each step of their journey brings them closer to an even bigger threat - and the shattering truth of their own destiny.