William Gilkerson's Ultimate Voyage, subtitled A Book of Five Mariners (Shambhala, 314 pages, $35 cloth), is an allegorical adventure story with a magical twist. Gilkerson, who lives in Nova Scotia and is the author of ten non-fiction books about subjects nautical, remains immersed in the element he knows well: the sea.

Five boys are born at the same moment into a period reminiscent of the Renaissance and grow up in Port, "a place less of the land than of the ocean". In their teens, an oracle prophesies that they will embark on an important voyage together when they grow up. The prophecy comes true, but the boys-now young men-have no idea just how much the journey will affect them, both as individuals and as a group. Pilot, the philosopher, alchemist, and seeker of truth is both instigator and navigator. It is he who builds a unique sailing vessel, calls it Alembic ("the crucible of purification in which the alchemist is said to convert lead to gold"), and suggests the five go on the "ultimate voyage", which is in part a quest to discover how "nothing is everything" and how there is no "reward more rewarding than the process" itself.