Following word that his father had been injured in a Japanese air raid on the mainland of China, Rance Warren immediately set out from California to join his beleaguered parents. Forced to work his way across the Pacific as a wiper in the engine room of the tanker Zambora, Rance unwittingly became implicated in a nasty scuffle with the second engineer and the steward. Weathering storms and entangled in intrigue, Rance, along with Captain Jarvis and Tod Moran, faces evil and dangerous men aboard The Black Tanker.