Captain Rhama Sabrier is hired by the
scholar Dr. Areliano to help him study a mysterious boat in his possession. There is a massive tree inside of the boat from which grows mystical herbs (Rhama names the boat the Treeship in respect to this fact), which Areliano wishes to study for their scientific merit. Areliano's assistant Jabez kills the scholar and steals the Treeship out of greed, and Rhama pursues him both to stop his plans and to learn the Treeship's origins. Although he catches up to Jabez several times, Rhama is repeatedly thwarted by the godlike powers Jabez harnesses by consuming the Treeship's herbs. Rhama and his crew travel to many islands on their journey, and several people join them: Faith, a
healer and Dr. Areliano's daughter; Calverly, a
shipwright and Rhama's friend who is transformed into a monkey by Jabez; and the
martial artist Mihoko, who is rescued from an island of slaves and swears her life to Rhama. Eventually, Rhama and his crew discover that an ancient civilization had cultivated the herbs as a source of energy and
eternal life, and that they were using the Treeship to transport the only tree that can be
cross-pollinated with the dying sacred tree, located on the island of Epheremy. The heroes sail to Epheremy and confront Jabez, who threatened its inhabitants into taking him to the site of the sacred tree. Jabez consumes the sacred tree's just-bloomed flower to gain immense power, but is nevertheless defeated and killed by Rhama. Jabez's corpse produces seeds that can grow more of the Treeship's trees, meaning that Epheremy's inhabitants now have immediate access its herbs and the sacred tree is saved. Later, Rhama and his crew bury the treasure that they had accumulated, and Rhama and Faith are implied to have become lovers. ==Development==