In 1898, in the middle of the Spanish-American War, sea pilot Peter Long receives a mysterious request for his services. He is asked to guide a three-masted coasting schooner to the ocean's mouth. The ship's master is none other than Eben Soule, Long's old rival from their days as apprentices aboard the pilot schooner Tunnell.
A pacifist Quaker sympathizer, Soule is ousted from the pilot service for his activist ways. Despite past rivalries, including competition for the love of the daughter of a wealthy Quaker ship owner, Soule secretly remains a hero for Long. The crew suspects Soule to be involved with aiding the enemy, and the schooner's true landfall to be Cuba. When Spanish voices are heard in a locked part of the hold, mutiny appears imminent.
What unfolds is a story of friendship, competition, and conflict in which Long must look past old feelings and decide where his loyalties lie.