Kenneth Wayne is the captain of a trading ship plying the waters of the Malayan archipelago. The ship is attacked by pirates and Wayne’s father is killed. Wayne vows revenge. His plan involves posing as a gold hunter as a ruse to search Malay villages unsuspected, but he rather overestimates his own ability and is forever being rescued by his much more skillful guide, an Indian named Gulab Singh.
Wayne becomes involved in a mystery — the discovery (and loss) of the fabled Itu Konchi-kan Kitab, or The Locked Book, a sort of treasure map left by a prolific pirate from generations past. Two men are killed for it, a Malay and a white man, and Wayne becomes the target of a manhunt on both sides. Gulab Singh helps him escape into the jungle, but they are cornered by the pirates, who believe that Wayne still has the book.
As it so happens, Gulab Singh has it, and he arranges an exchange with the pirates — the book for their lives. You see, Gulab Singh’s wife and child were also killed by the pirates and he also vowed revenge. He spent years forging The Locked Book perfectly, only it did not contain the key to lost treasures, but rather high explosives rigged to detonate on opening. Gulab Singh orchestrated almost everything and was using Wayne as a means of massing the pirates together and getting the booby-trapped book into their hands.