The Oaql Seed

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.