Arionella is an unwitting passenger aboard a sentient treeboat, a mobile species of the plant kingdom cultivated by the indigenous Reteti of the Haelin Islands. The treeboat's appetite for human consciousness seems to explain why it has whisked off a child to the Cyan Sea, but when the spirit of her missing grandmother appears onboard it becomes apparent that greater forces are influencing the lives of Arionella and her adoptive family, who are willing to risk everything to save her.

Swept off by a sentient treeboat to the vast Cyan sea, twelve-year-old Arionella's predicament is a terrible one. Curiously, the fierce currents and storms of the open ocean do not present a danger to her, treeboats can easily sense and avoid perils such as these. It is the Oaql tree itself that is a danger to the child onboard, seeking to assimilate her human consciousness into its biology. Taola Lonwë, the captain of the Oaql boat, knows that the treeboats are not inherently evil. In fact, treeboats are valuable bioremediators cultivated by the Reteti Islanders, who have long been stewards of the Earth and have worked diligently to purify "sick waters" that are the legacies of ancient devastations. Arionella's unexpected departure rapidly ties in with a more encompassing and sinister series of events that her missing grandparents, Maya and Jöshi, have long been investigating. A man familiar with ancient shamanic arts, Revalo Otrebor uses his abilities to lead the Cult of Knoa, a legion of followers whom he claims to rescue from troubled, medicated lives, in cityforts. Even the wise were fooled in the early days of his ascendancy but having amassed his strength over the course of decades, he now moves with purpose and open aggression, collecting objects and beings of power for himself, including hunting down the set of a dozen treeboats. Can Taola lead Arionella's adoptive family across the ocean and across lawless lands before Revalo finds the Oaql boat first, and before Arionella loses her sense of self to the Oaql tree?

Z.A. Ispharazi's writings spring from a heart deeply moved by indigenous wisdom while doing rogue anthropology in South America. Inspired by the mystique of the Amazonian Rainforest, where late-night lore by candlelight is still common, the Treeboat world began to unfold from the pages of his journals. He currently lives in New York with his wife, where he finds great joy in tending to his garden, trail running, and facilitating the integration of indigenous wisdom into the globalized community.