Hordes of a deadly and unknown species of predator swarm across Twilight, killing and destroying everything in their path. Where have they come from? Is there a connection with the Final Faith airship in the Drakengrat Mountains? What was 'the mistake'? Exactly what are the k'nid – and how can they be stopped?

New questions for Kali Hooper and her friends to answer – but doing so will prove far from easy. From a labyrinthine dwarven deathtrap to a besieged and battle-torn city, a haunted ancient limbo at the end of time and the aquatic lair of a vast serpent, Kali must battle her way to a place in the clouds that legend calls the Crucible of the Dragon God. There she must confront the past itself, for the Crucible holds a secret kept even from the Old Races – a secret so staggering that Kali is about to discover the true reason her world is called Twilight...