As in The Golden Ocean, The Unknown Shore tells the tale of another ill-fated ship on Anson's expedition round the world - the Wager. Parted from her squadron in the fearful storms off Cape Horn, the Wager struggles on alone up the ironbound coast of Chile, before she is driven onto rocks and sinks. The survivors include Jack Byron, a midshipman, and his eccentric protege Toby, an alarmingly naive surgeon's mate with a single-minded devotion to zoology. Faced with a surplus of rum, a disappearing stock of food, and a hard, detested captain, the survivors soon descend into trouble of every kind, including drunkeness, mutiny and bloodshed. As they make their way northwards under the guidance of a band of stony and depraved Indians, they at last find safety and good treatment in Valparaiso.