Fifteen-year-old orphan John Trenchard grows up in a smuggler's den called Moonfleet. The people in the village tell stories that the churchyard is haunted by the ghost of the notorious Colonel Mohune, who hid a treasure there before his death. By chance, John Trenchard discovers the family crypt of the Mohunes, which also serves as a hideout for smugglers. In the Colonel's coffin, he finds an amulet with a mysterious parchment, from which he hopes to gain insight into the whereabouts of the treasure. However, he cannot free himself from the crypt and is only rescued by smugglers after several days. Elzevir Block, their leader, takes the young Trenchard under his wing. When the two fall into an ambush, they can only narrowly escape from the Crown's soldiers. Severely injured, John Trenchard is taken by Elzevir to a secret hideout.