Kensho arrives at the Crystal Castle where he was once a lowly acolyte and is asked to accept the responsibility as leader of Thra. But he will have to rectify sins of the past before he can decide if he – or anyone – is fit to rule. Meanwhile, the realm of Mithra is being rebuilt by the newly-crowned Ember Queen Thurma, whose own quest to decide the future of her land is thrown into question when another Fireling makes a claim as the true heir to the throne.