The winged werewolf Lun has finally found a home. Once a solitary wanderer, he is now the consort of Nephrite, queen-sister of the court of the Indigo Mist. Together with their people, they set off on flying ships on a journey to find a new home for the Raksura colony. However, upon arriving at the goal, the ancestral home of the tribe in the trunk of a gigantic tree, the travelers discover that it is rotting from the inside. And that is not all. Frightening discoveries force Luna and the Raksur warriors to set out in search of the heart of the tree - a search that will take them far, far, beyond the Serpent Sea. In this sequel novel to Roads of Clouds, Martha Wells invites readers to travel across the world, solve the mystery, the answer to which only leads to new questions, and take part in an unforgettable adventure.